diff --git a/src/driver/blackbox/m25p16.c b/src/driver/blackbox/m25p16.c
index 0c8ddad11..9316ee272 100644
--- a/src/driver/blackbox/m25p16.c
+++ b/src/driver/blackbox/m25p16.c
@@ -47,13 +47,9 @@ bool m25p16_is_ready() {
   }
 
   static uint8_t buffer[2];
-  const spi_txn_segment_t segs[] = {
-      spi_make_seg_buffer(buffer, buffer, 2),
-  };
-  const bool is_done = spi_seg_submit_check(&bus, segs, {
+  const bool is_done = spi_seg_submit_check(&bus, { spi_make_seg_buffer(buffer, buffer, 2); }, {
     buffer[0] = M25P16_READ_STATUS_REGISTER;
-    buffer[1] = 0xFF;
-  });
+    buffer[1] = 0xFF; });
   if (!is_done) {
     return false;
   }
@@ -69,12 +65,9 @@ uint8_t m25p16_command(const uint8_t cmd) {
   m25p16_wait_for_ready();
 
   uint8_t ret = 0;
-
-  const spi_txn_segment_t segs[] = {
-      spi_make_seg_buffer(&ret, &cmd, 1),
-  };
-  spi_seg_submit_wait(&bus, segs);
-
+  spi_seg_submit_wait(&bus, {
+    spi_make_seg_buffer(&ret, &cmd, 1);
+  });
   return ret;
 }
 
@@ -82,13 +75,10 @@ uint8_t m25p16_read_command(const uint8_t cmd, uint8_t *data, const uint32_t len
   m25p16_wait_for_ready();
 
   uint8_t ret = 0;
-
-  const spi_txn_segment_t segs[] = {
-      spi_make_seg_buffer(&ret, &cmd, 1),
-      spi_make_seg_buffer(data, NULL, len),
-  };
-  spi_seg_submit_wait(&bus, segs);
-
+  spi_seg_submit_wait(&bus, {
+    spi_make_seg_buffer(&ret, &cmd, 1);
+    spi_make_seg_buffer(data, NULL, len);
+  });
   return ret;
 }
 
@@ -96,14 +86,11 @@ uint8_t m25p16_read_addr(const uint8_t cmd, const uint32_t addr, uint8_t *data,
   m25p16_wait_for_ready();
 
   uint8_t ret = 0;
-
-  const spi_txn_segment_t segs[] = {
-      spi_make_seg_buffer(&ret, &cmd, 1),
-      spi_make_seg_const(m25p16_addr(addr)),
-      spi_make_seg_buffer(data, NULL, len),
-  };
-  spi_seg_submit_wait(&bus, segs);
-
+  spi_seg_submit_wait(&bus, {
+    spi_make_seg_buffer(&ret, &cmd, 1);
+    spi_make_seg_const(m25p16_addr(addr));
+    spi_make_seg_buffer(data, NULL, len);
+  });
   return ret;
 }
 
@@ -112,22 +99,15 @@ bool m25p16_page_program(const uint32_t addr, const uint8_t *buf, const uint32_t
     return false;
   }
 
-  {
-    const spi_txn_segment_t segs[] = {
-        spi_make_seg_const(M25P16_WRITE_ENABLE),
-    };
-    spi_seg_submit(&bus, segs);
-  }
-
-  {
-    const spi_txn_segment_t segs[] = {
-        spi_make_seg_const(M25P16_PAGE_PROGRAM, m25p16_addr(addr)),
-        spi_make_seg_buffer(NULL, buf, size),
-    };
-    spi_seg_submit(&bus, segs);
-  }
-
+  spi_seg_submit(&bus, {
+    spi_make_seg_const(M25P16_WRITE_ENABLE);
+  });
+  spi_seg_submit(&bus, {
+    spi_make_seg_const(M25P16_PAGE_PROGRAM, m25p16_addr(addr));
+    spi_make_seg_buffer(NULL, buf, size);
+  });
   spi_txn_continue(&bus);
+
   return true;
 }
 
@@ -136,21 +116,15 @@ bool m25p16_write_addr(const uint8_t cmd, const uint32_t addr, uint8_t *data, co
     return false;
   }
 
-  {
-    const spi_txn_segment_t segs[] = {
-        spi_make_seg_const(M25P16_WRITE_ENABLE),
-    };
-    spi_seg_submit(&bus, segs);
-  }
-  {
-    const spi_txn_segment_t segs[] = {
-        spi_make_seg_const(cmd, m25p16_addr(addr)),
-        spi_make_seg_buffer(NULL, data, len),
-    };
-    spi_seg_submit(&bus, segs);
-  }
-
+  spi_seg_submit(&bus, {
+    spi_make_seg_const(M25P16_WRITE_ENABLE);
+  });
+  spi_seg_submit(&bus, {
+    spi_make_seg_const(cmd, m25p16_addr(addr));
+    spi_make_seg_buffer(NULL, data, len);
+  });
   spi_txn_continue(&bus);
+
   return true;
 }
 
@@ -159,19 +133,12 @@ bool m25p16_chip_erase() {
     return false;
   }
 
-  {
-    const spi_txn_segment_t segs[] = {
-        spi_make_seg_const(M25P16_WRITE_ENABLE),
-    };
-    spi_seg_submit(&bus, segs);
-  }
-  {
-    const spi_txn_segment_t segs[] = {
-        spi_make_seg_const(M25P16_BULK_ERASE),
-    };
-    spi_seg_submit(&bus, segs);
-  }
-
+  spi_seg_submit(&bus, {
+    spi_make_seg_const(M25P16_WRITE_ENABLE);
+  });
+  spi_seg_submit(&bus, {
+    spi_make_seg_const(M25P16_BULK_ERASE);
+  });
   spi_txn_continue(&bus);
   return true;
 }
diff --git a/src/driver/blackbox/sdcard.c b/src/driver/blackbox/sdcard.c
index 76d7e6700..df30fd845 100644
--- a/src/driver/blackbox/sdcard.c
+++ b/src/driver/blackbox/sdcard.c
@@ -91,19 +91,15 @@ static bool sdcard_read_detect() {
 }
 
 static uint8_t sdcard_wait_non_idle() {
-  uint8_t ret = 0;
-
-  const spi_txn_segment_t segs[] = {
-      spi_make_seg_buffer(&ret, NULL, 1),
-  };
-
   for (uint16_t timeout = 8;; timeout--) {
     if (timeout == 0) {
       return 0xFF;
     }
 
-    spi_seg_submit_wait(&bus, segs);
-
+    uint8_t ret = 0;
+    spi_seg_submit_wait(&bus, {
+      spi_make_seg_buffer(&ret, NULL, 1);
+    });
     if (ret != 0xFF) {
       return ret;
     }
@@ -112,19 +108,15 @@ static uint8_t sdcard_wait_non_idle() {
 }
 
 static bool sdcard_wait_for_idle() {
-  uint8_t ret = 0;
-
-  const spi_txn_segment_t segs[] = {
-      spi_make_seg_buffer(&ret, NULL, 1),
-  };
-
   for (uint16_t timeout = 8;; timeout--) {
     if (timeout == 0) {
       return 0;
     }
 
-    spi_seg_submit_wait(&bus, segs);
-
+    uint8_t ret = 0;
+    spi_seg_submit_wait(&bus, {
+      spi_make_seg_buffer(&ret, NULL, 1);
+    });
     if (ret == 0xFF) {
       return true;
     }
@@ -137,34 +129,31 @@ static uint8_t sdcard_command(const uint8_t cmd, const uint32_t args) {
     return 0xFF;
   }
 
-  uint32_t count = 0;
-  spi_txn_segment_t segs[3] = {};
-
-  segs[count++] = spi_make_seg_const(
-      0x40 | cmd,
-      args >> 24,
-      args >> 16,
-      args >> 8,
-      args >> 0);
-
-  // we have to send CRC while we are still in SD Bus mode
-  switch (cmd) {
-  case SDCARD_GO_IDLE:
-    segs[count++] = spi_make_seg_const(0x95);
-    break;
-  case SDCARD_IF_COND:
-    segs[count++] = spi_make_seg_const(0x87);
-    break;
-  default:
-    segs[count++] = spi_make_seg_const(1);
-    break;
-  }
+  spi_seg_submit_wait(&bus, {
+    spi_make_seg_const(
+        0x40 | cmd,
+        args >> 24,
+        args >> 16,
+        args >> 8,
+        args >> 0);
 
-  if (cmd == SDCARD_STOP_TRANSMISSION) {
-    segs[count++] = spi_make_seg_const(0xFF);
-  }
+    // we have to send CRC while we are still in SD Bus mode
+    switch (cmd) {
+    case SDCARD_GO_IDLE:
+      spi_make_seg_const(0x95);
+      break;
+    case SDCARD_IF_COND:
+      spi_make_seg_const(0x87);
+      break;
+    default:
+      spi_make_seg_const(1);
+      break;
+    }
 
-  spi_seg_submit_wait_ex(&bus, segs, count);
+    if (cmd == SDCARD_STOP_TRANSMISSION) {
+      spi_make_seg_const(0xFF);
+    }
+  });
 
   return sdcard_wait_non_idle();
 }
@@ -176,12 +165,9 @@ static uint8_t sdcard_app_command(const uint8_t cmd, const uint32_t args) {
 
 uint32_t sdcard_read_response() {
   uint8_t buf[4];
-
-  const spi_txn_segment_t segs[] = {
-      spi_make_seg_buffer(buf, NULL, 4),
-  };
-  spi_seg_submit_wait(&bus, segs);
-
+  spi_seg_submit_wait(&bus, {
+    spi_make_seg_buffer(buf, NULL, 4);
+  });
   return (buf[0] << 24) | (buf[1] << 16) | (buf[2] << 8) | (buf[3] << 0);
 }
 
@@ -192,28 +178,23 @@ void sdcard_read_data(uint8_t *buf, const uint32_t size) {
     return;
   }
 
-  const spi_txn_segment_t segs[] = {
-      spi_make_seg_buffer(buf, NULL, size),
-      // two bytes CRC
-      spi_make_seg_const(0xFF, 0xFF),
-  };
-  spi_seg_submit_wait(&bus, segs);
+  spi_seg_submit_wait(&bus, {
+    spi_make_seg_buffer(buf, NULL, size);
+    // two bytes CRC
+    spi_make_seg_const(0xFF, 0xFF);
+  });
 }
 
 void sdcard_write_data(const uint8_t token, const uint8_t *buf, const uint32_t size) {
-  const spi_txn_segment_t segs[] = {
-      // start block
-      spi_make_seg_const(token),
-
-      spi_make_seg_buffer(NULL, (uint8_t *)buf, size),
-
-      // two bytes CRC
-      spi_make_seg_const(0xFF, 0xFF),
-
-      // write response
-      spi_make_seg_const(0xFF),
-  };
-  spi_seg_submit_wait(&bus, segs);
+  spi_seg_submit_wait(&bus, {
+    // start block
+    spi_make_seg_const(token);
+    spi_make_seg_buffer(NULL, (uint8_t *)buf, size);
+    // two bytes CRC
+    spi_make_seg_const(0xFF, 0xFF);
+    // write response
+    spi_make_seg_const(0xFF);
+  });
 }
 
 static void sdcard_parse_csd(sdcard_csd_t *csd, uint8_t *c) {
@@ -300,11 +281,10 @@ sdcard_status_t sdcard_update() {
     }
 
     const uint8_t buf[20] = {[RANGE_INIT(0, 20)] = 0xff};
-    const spi_txn_segment_t segs[] = {
-        spi_make_seg_buffer(NULL, buf, 20),
-    };
-    spi_seg_submit_continue(&bus, segs);
-
+    spi_seg_submit(&bus, {
+      spi_make_seg_buffer(NULL, buf, 20);
+    });
+    spi_txn_continue(&bus);
     state = SDCARD_RESET;
     delay_loops = 100;
     tries++;
@@ -405,14 +385,13 @@ sdcard_status_t sdcard_update() {
     uint8_t token = sdcard_wait_non_idle();
     if (token == 0xFE) {
       state = SDCARD_READ_MULTIPLE_CONTINUE;
+      spi_seg_submit(&bus, {
+        spi_make_seg_buffer(operation.buf + operation.count_done * SDCARD_PAGE_SIZE, NULL, SDCARD_PAGE_SIZE);
 
-      const spi_txn_segment_t segs[] = {
-          spi_make_seg_buffer(operation.buf + operation.count_done * SDCARD_PAGE_SIZE, NULL, SDCARD_PAGE_SIZE),
-
-          // two bytes CRC
-          spi_make_seg_const(0xFF, 0xFF),
-      };
-      spi_seg_submit_continue(&bus, segs);
+        // two bytes CRC
+        spi_make_seg_const(0xFF, 0xFF);
+      });
+      spi_txn_continue(&bus);
     }
     break;
   }
@@ -462,19 +441,19 @@ sdcard_status_t sdcard_update() {
       break;
     }
 
-    const spi_txn_segment_t segs[] = {
-        // token
-        spi_make_seg_const(0xFC),
+    spi_seg_submit(&bus, {
+      // token
+      spi_make_seg_const(0xFC);
 
-        spi_make_seg_buffer(NULL, operation.buf, SDCARD_PAGE_SIZE),
+      spi_make_seg_buffer(NULL, operation.buf, SDCARD_PAGE_SIZE);
 
-        // two bytes CRC
-        spi_make_seg_const(0xFF, 0xFF),
+      // two bytes CRC
+      spi_make_seg_const(0xFF, 0xFF);
 
-        // write response
-        spi_make_seg_const(0xFF),
-    };
-    spi_seg_submit_continue(&bus, segs);
+      // write response
+      spi_make_seg_const(0xFF);
+    });
+    spi_txn_continue(&bus);
 
     state = SDCARD_WRITE_MULTIPLE_VERIFY;
     break;
@@ -491,11 +470,10 @@ sdcard_status_t sdcard_update() {
   }
 
   case SDCARD_WRITE_MULTIPLE_FINISH: {
-    const spi_txn_segment_t segs[] = {
-        spi_make_seg_const(0xFD),
-    };
-    spi_seg_submit_continue(&bus, segs);
-
+    spi_seg_submit(&bus, {
+      spi_make_seg_const(0xFD);
+    });
+    spi_txn_continue(&bus);
     state = SDCARD_WRITE_MULTIPLE_FINISH_WAIT;
     break;
   }
diff --git a/src/driver/gyro/bmi270.c b/src/driver/gyro/bmi270.c
index 0e577dc47..62726d829 100644
--- a/src/driver/gyro/bmi270.c
+++ b/src/driver/gyro/bmi270.c
@@ -130,10 +130,9 @@ uint8_t bmi270_read(uint8_t reg) {
 
   uint8_t buffer[3] = {reg | 0x80, 0x0, 0x0};
 
-  const spi_txn_segment_t segs[] = {
-      spi_make_seg_buffer(buffer, buffer, 3),
-  };
-  spi_seg_submit_wait(&gyro_bus, segs);
+  spi_seg_submit_wait(&gyro_bus, {
+    spi_make_seg_buffer(buffer, buffer, 3);
+  });
 
   return buffer[2];
 }
@@ -142,57 +141,43 @@ uint16_t bmi270_read16(uint8_t reg) {
   spi_bus_device_reconfigure(&gyro_bus, SPI_MODE_TRAILING_EDGE, SPI_SPEED_SLOW);
 
   uint8_t buffer[4] = {reg | 0x80, 0x0, 0x0, 0x0};
-
-  const spi_txn_segment_t segs[] = {
-      spi_make_seg_buffer(buffer, buffer, 4),
-  };
-  spi_seg_submit_wait(&gyro_bus, segs);
-
+  spi_seg_submit_wait(&gyro_bus, {
+    spi_make_seg_buffer(buffer, buffer, 4);
+  });
   return ((buffer[3] << 8) | buffer[2]);
 }
 
 void bmi270_write(uint8_t reg, uint8_t data, uint32_t delay) {
   spi_bus_device_reconfigure(&gyro_bus, SPI_MODE_TRAILING_EDGE, SPI_SPEED_SLOW);
-
-  const spi_txn_segment_t segs[] = {
-      spi_make_seg_const(reg, data),
-  };
-  spi_seg_submit_wait(&gyro_bus, segs);
-
+  spi_seg_submit_wait(&gyro_bus, {
+    spi_make_seg_const(reg, data);
+  });
   time_delay_ms(delay);
 }
 
 void bmi270_write16(uint8_t reg, uint16_t data, uint32_t delay) {
   spi_bus_device_reconfigure(&gyro_bus, SPI_MODE_TRAILING_EDGE, SPI_SPEED_SLOW);
-
-  const spi_txn_segment_t segs[] = {
-      spi_make_seg_const(reg, data & 0xff, data >> 8),
-  };
-  spi_seg_submit_wait(&gyro_bus, segs);
-
+  spi_seg_submit_wait(&gyro_bus, {
+    spi_make_seg_const(reg, data & 0xff, data >> 8);
+  });
   time_delay_ms(delay);
 }
 
 void bmi270_write_data(uint8_t reg, uint8_t *data, uint32_t size, uint32_t delay) {
   spi_bus_device_reconfigure(&gyro_bus, SPI_MODE_TRAILING_EDGE, SPI_SPEED_SLOW);
-
-  const spi_txn_segment_t segs[] = {
-      spi_make_seg_const(reg),
-      spi_make_seg_buffer(NULL, data, size),
-  };
-  spi_seg_submit_wait(&gyro_bus, segs);
-
+  spi_seg_submit_wait(&gyro_bus, {
+    spi_make_seg_const(reg);
+    spi_make_seg_buffer(NULL, data, size);
+  });
   time_delay_ms(delay);
 }
 
 void bmi270_read_data(uint8_t reg, uint8_t *data, uint32_t size) {
   spi_bus_device_reconfigure(&gyro_bus, SPI_MODE_TRAILING_EDGE, SPI_SPEED_FAST);
-
-  const spi_txn_segment_t segs[] = {
-      spi_make_seg_const(reg | 0x80, 0xFF),
-      spi_make_seg_buffer(data, NULL, size),
-  };
-  spi_seg_submit_wait(&gyro_bus, segs);
+  spi_seg_submit_wait(&gyro_bus, {
+    spi_make_seg_const(reg | 0x80, 0xFF);
+    spi_make_seg_buffer(data, NULL, size);
+  });
 }
 
 void bmi270_read_gyro_data(gyro_data_t *data) {
@@ -224,21 +209,14 @@ void bmi270_read_gyro_data(gyro_data_t *data) {
 
   data->temp = (float)((int16_t)((gyro_buf[13] << 8) | gyro_buf[12])) / 512.0 + 23.0;
 
-  {
-    const spi_txn_segment_t segs[] = {
-        spi_make_seg_const(BMI270_REG_ACC_DATA_X_LSB | 0x80, 0xFF),
-        spi_make_seg_buffer(gyro_buf, NULL, 12),
-    };
-    spi_seg_submit(&gyro_bus, segs);
-  }
-  {
-    const spi_txn_segment_t segs[] = {
-        spi_make_seg_const(BMI270_REG_TEMPERATURE_LSB | 0x80, 0xFF),
-        spi_make_seg_buffer(gyro_buf + 12, NULL, 2),
-    };
-    spi_seg_submit(&gyro_bus, segs);
-  }
-
+  spi_seg_submit(&gyro_bus, {
+    spi_make_seg_const(BMI270_REG_ACC_DATA_X_LSB | 0x80, 0xFF);
+    spi_make_seg_buffer(gyro_buf, NULL, 12);
+  });
+  spi_seg_submit(&gyro_bus, {
+    spi_make_seg_const(BMI270_REG_TEMPERATURE_LSB | 0x80, 0xFF);
+    spi_make_seg_buffer(gyro_buf + 12, NULL, 2);
+  });
   while (!spi_txn_continue(&gyro_bus))
     ;
 }
diff --git a/src/driver/gyro/bmi323.c b/src/driver/gyro/bmi323.c
index 481cb8fe6..e4a7fdd6f 100644
--- a/src/driver/gyro/bmi323.c
+++ b/src/driver/gyro/bmi323.c
@@ -111,10 +111,9 @@ uint8_t bmi3_read8(uint8_t reg) {
 
   uint8_t buffer[3] = {reg | 0x80, 0x0, 0x0};
 
-  const spi_txn_segment_t segs[] = {
-      spi_make_seg_buffer(buffer, buffer, 3),
-  };
-  spi_seg_submit_wait(&gyro_bus, segs);
+  spi_seg_submit_wait(&gyro_bus, {
+    spi_make_seg_buffer(buffer, buffer, 3);
+  });
 
   return buffer[2];
 }
@@ -123,57 +122,44 @@ uint16_t bmi3_read16(uint8_t reg) {
   spi_bus_device_reconfigure(&gyro_bus, SPI_MODE_TRAILING_EDGE, SPI_SPEED_SLOW);
 
   uint8_t buffer[4] = {reg | 0x80, 0x0, 0x0, 0x0};
-
-  const spi_txn_segment_t segs[] = {
-      spi_make_seg_buffer(buffer, buffer, 4),
-  };
-  spi_seg_submit_wait(&gyro_bus, segs);
-
+  spi_seg_submit_wait(&gyro_bus, {
+    spi_make_seg_buffer(buffer, buffer, 4);
+  });
   return ((buffer[3] << 8) | buffer[2]);
 }
 
 void bmi3_write8(uint8_t reg, uint8_t data, uint32_t delay) {
   spi_bus_device_reconfigure(&gyro_bus, SPI_MODE_TRAILING_EDGE, SPI_SPEED_SLOW);
-
-  const spi_txn_segment_t segs[] = {
-      spi_make_seg_const(reg, data),
-  };
-  spi_seg_submit_wait(&gyro_bus, segs);
-
+  spi_seg_submit_wait(&gyro_bus, {
+    spi_make_seg_const(reg, data);
+  });
   time_delay_ms(delay);
 }
 
 void bmi3_write16(uint8_t reg, uint16_t data, uint32_t delay) {
   spi_bus_device_reconfigure(&gyro_bus, SPI_MODE_TRAILING_EDGE, SPI_SPEED_SLOW);
-
-  const spi_txn_segment_t segs[] = {
-      spi_make_seg_const(reg, data & 0xff, data >> 8),
-  };
-  spi_seg_submit_wait(&gyro_bus, segs);
-
+  spi_seg_submit_wait(&gyro_bus, {
+    spi_make_seg_const(reg, data & 0xff, data >> 8);
+  });
   time_delay_ms(delay);
 }
 
 void bmi3_write_data(uint8_t reg, uint8_t *data, uint32_t size, uint32_t delay) {
   spi_bus_device_reconfigure(&gyro_bus, SPI_MODE_TRAILING_EDGE, SPI_SPEED_SLOW);
-
-  const spi_txn_segment_t segs[] = {
-      spi_make_seg_const(reg),
-      spi_make_seg_buffer(NULL, data, size),
-  };
-  spi_seg_submit_wait(&gyro_bus, segs);
-
+  spi_seg_submit_wait(&gyro_bus, {
+    spi_make_seg_const(reg);
+    spi_make_seg_buffer(NULL, data, size);
+  });
   time_delay_ms(delay);
 }
 
 void bmi3_read_data(uint8_t reg, uint8_t *data, uint32_t size) {
   spi_bus_device_reconfigure(&gyro_bus, SPI_MODE_TRAILING_EDGE, SPI_SPEED_FAST);
 
-  const spi_txn_segment_t segs[] = {
-      spi_make_seg_const(reg | 0x80, 0xFF),
-      spi_make_seg_buffer(data, NULL, size),
-  };
-  spi_seg_submit_wait(&gyro_bus, segs);
+  spi_seg_submit_wait(&gyro_bus, {
+    spi_make_seg_const(reg | 0x80, 0xFF);
+    spi_make_seg_buffer(data, NULL, size);
+  });
 }
 
 void bmi323_read_gyro_data(gyro_data_t *data) {
@@ -205,11 +191,10 @@ void bmi323_read_gyro_data(gyro_data_t *data) {
 
   data->temp = 0;
 
-  const spi_txn_segment_t segs[] = {
-      spi_make_seg_const(BMI323_REG_ACC_DATA_X_LSB | 0x80, 0xFF),
-      spi_make_seg_buffer(gyro_buf, NULL, 12),
-  };
-  spi_seg_submit(&gyro_bus, segs);
+  spi_seg_submit(&gyro_bus, {
+    spi_make_seg_const(BMI323_REG_ACC_DATA_X_LSB | 0x80, 0xFF);
+    spi_make_seg_buffer(gyro_buf, NULL, 12);
+  });
   while (!spi_txn_continue(&gyro_bus))
     ;
 }
diff --git a/src/driver/gyro/icm42605.c b/src/driver/gyro/icm42605.c
index 8bdfcc490..0246f84f8 100644
--- a/src/driver/gyro/icm42605.c
+++ b/src/driver/gyro/icm42605.c
@@ -89,22 +89,17 @@ uint8_t icm42605_read(uint8_t reg) {
   spi_bus_device_reconfigure(&gyro_bus, SPI_MODE_TRAILING_EDGE, SPI_SPEED_SLOW);
 
   uint8_t buffer[2] = {reg | 0x80, 0x00};
-
-  const spi_txn_segment_t segs[] = {
-      spi_make_seg_buffer(buffer, buffer, 2),
-  };
-  spi_seg_submit_wait(&gyro_bus, segs);
-
+  spi_seg_submit_wait(&gyro_bus, {
+    spi_make_seg_buffer(buffer, buffer, 2);
+  });
   return buffer[1];
 }
 
 void icm42605_write(uint8_t reg, uint8_t data) {
   spi_bus_device_reconfigure(&gyro_bus, SPI_MODE_TRAILING_EDGE, SPI_SPEED_SLOW);
-
-  const spi_txn_segment_t segs[] = {
-      spi_make_seg_const(reg, data),
-  };
-  spi_seg_submit_wait(&gyro_bus, segs);
+  spi_seg_submit_wait(&gyro_bus, {
+    spi_make_seg_const(reg, data);
+  });
 }
 
 void icm42605_read_gyro_data(gyro_data_t *data) {
@@ -121,11 +116,10 @@ void icm42605_read_gyro_data(gyro_data_t *data) {
   data->gyro.roll = (int16_t)((gyro_buf[10] << 8) | gyro_buf[11]);
   data->gyro.yaw = (int16_t)((gyro_buf[12] << 8) | gyro_buf[13]);
 
-  const spi_txn_segment_t segs[] = {
-      spi_make_seg_const(ICM42605_TEMP_DATA1 | 0x80),
-      spi_make_seg_buffer(gyro_buf, NULL, 14),
-  };
-  spi_seg_submit(&gyro_bus, segs);
+  spi_seg_submit(&gyro_bus, {
+    spi_make_seg_const(ICM42605_TEMP_DATA1 | 0x80);
+    spi_make_seg_buffer(gyro_buf, NULL, 14);
+  });
   while (!spi_txn_continue(&gyro_bus))
     ;
 }
diff --git a/src/driver/gyro/mpu6xxx.c b/src/driver/gyro/mpu6xxx.c
index dcaf6bb1a..4dccd4926 100644
--- a/src/driver/gyro/mpu6xxx.c
+++ b/src/driver/gyro/mpu6xxx.c
@@ -93,23 +93,18 @@ uint8_t mpu6xxx_read(uint8_t reg) {
   spi_bus_device_reconfigure(&gyro_bus, SPI_MODE_TRAILING_EDGE, SPI_SPEED_INIT);
 
   uint8_t buffer[2] = {reg | 0x80, 0x00};
-
-  const spi_txn_segment_t segs[] = {
-      spi_make_seg_buffer(buffer, buffer, 2),
-  };
-  spi_seg_submit_wait(&gyro_bus, segs);
-
+  spi_seg_submit_wait(&gyro_bus, {
+    spi_make_seg_buffer(buffer, buffer, 2);
+  });
   return buffer[1];
 }
 
 // blocking dma write of a single register
 void mpu6xxx_write(uint8_t reg, uint8_t data) {
   spi_bus_device_reconfigure(&gyro_bus, SPI_MODE_TRAILING_EDGE, SPI_SPEED_INIT);
-
-  const spi_txn_segment_t segs[] = {
-      spi_make_seg_const(reg, data),
-  };
-  spi_seg_submit_wait(&gyro_bus, segs);
+  spi_seg_submit_wait(&gyro_bus, {
+    spi_make_seg_const(reg, data);
+  });
 }
 
 void mpu6xxx_read_gyro_data(gyro_data_t *data) {
@@ -126,11 +121,10 @@ void mpu6xxx_read_gyro_data(gyro_data_t *data) {
   data->gyro.roll = (int16_t)((gyro_buf[10] << 8) | gyro_buf[11]);
   data->gyro.yaw = (int16_t)((gyro_buf[12] << 8) | gyro_buf[13]);
 
-  const spi_txn_segment_t segs[] = {
-      spi_make_seg_const(MPU_RA_ACCEL_XOUT_H | 0x80),
-      spi_make_seg_buffer(gyro_buf, NULL, 14),
-  };
-  spi_seg_submit(&gyro_bus, segs);
+  spi_seg_submit(&gyro_bus, {
+    spi_make_seg_const(MPU_RA_ACCEL_XOUT_H | 0x80);
+    spi_make_seg_buffer(gyro_buf, NULL, 14);
+  });
   while (!spi_txn_continue(&gyro_bus))
     ;
 }
diff --git a/src/driver/mcu/at32/spi.c b/src/driver/mcu/at32/spi.c
index e829ddbd4..925993e49 100644
--- a/src/driver/mcu/at32/spi.c
+++ b/src/driver/mcu/at32/spi.c
@@ -228,50 +228,39 @@ void spi_device_init(spi_ports_t port) {
   interrupt_enable(dma_rx->irq, DMA_PRIORITY);
 }
 
-void spi_seg_submit_wait_ex(spi_bus_device_t *bus, const spi_txn_segment_t *segs, const uint32_t count) {
-  spi_txn_wait(bus);
+void spi_seg_transfer_start(spi_bus_device_t *bus) {
+  const spi_ports_t port = bus->port;
 
+  spi_txn_wait(bus);
   while (!spi_txn_can_send(bus, false))
     ;
 
-  const spi_ports_t port = bus->port;
-
   spi_dev[port].dma_done = false;
-
   spi_reconfigure(bus);
-
   spi_csn_enable(bus);
   spi_enable(spi_port_defs[port].channel, TRUE);
+}
 
-  for (uint32_t i = 0; i < count; i++) {
-    const spi_txn_segment_t *seg = &segs[i];
-    const uint32_t size = seg->size;
-
-    const uint8_t *tx_data = NULL;
-    uint8_t *rx_data = NULL;
-
-    if (seg->type == TXN_CONST) {
-      tx_data = seg->bytes;
-    } else {
-      tx_data = seg->tx_data;
-      rx_data = seg->rx_data;
-    }
+void spi_seg_transfer_bytes(spi_bus_device_t *bus, const uint8_t *tx_data, uint8_t *rx_data, const uint32_t size) {
+  const spi_ports_t port = bus->port;
 
-    for (uint32_t j = 0; j < size; j++) {
-      while (!spi_i2s_flag_get(spi_port_defs[port].channel, SPI_I2S_TDBE_FLAG))
-        ;
+  for (uint32_t i = 0; i < size; i++) {
+    while (!spi_i2s_flag_get(spi_port_defs[port].channel, SPI_I2S_TDBE_FLAG))
+      ;
 
-      spi_i2s_data_transmit(spi_port_defs[port].channel, tx_data ? tx_data[j] : 0xFF);
+    spi_i2s_data_transmit(spi_port_defs[port].channel, tx_data ? tx_data[i] : 0xFF);
 
-      while (!spi_i2s_flag_get(spi_port_defs[port].channel, SPI_I2S_RDBF_FLAG))
-        ;
+    while (!spi_i2s_flag_get(spi_port_defs[port].channel, SPI_I2S_RDBF_FLAG))
+      ;
 
-      const uint8_t ret = spi_i2s_data_receive(spi_port_defs[port].channel);
-      if (rx_data != NULL) {
-        rx_data[j] = ret;
-      }
-    }
+    const uint8_t ret = spi_i2s_data_receive(spi_port_defs[port].channel);
+    if (rx_data)
+      rx_data[i] = ret;
   }
+}
+
+void spi_seg_transfer_finish(spi_bus_device_t *bus) {
+  const spi_ports_t port = bus->port;
 
   spi_csn_disable(bus);
   spi_enable(spi_port_defs[port].channel, FALSE);
diff --git a/src/driver/mcu/stm32/spi.c b/src/driver/mcu/stm32/spi.c
index 2d195af02..7d3a71767 100644
--- a/src/driver/mcu/stm32/spi.c
+++ b/src/driver/mcu/stm32/spi.c
@@ -271,75 +271,65 @@ void spi_device_init(spi_ports_t port) {
   LL_DMA_EnableIT_TE(dma_rx->port, dma_rx->stream_index);
 }
 
-void spi_seg_submit_wait_ex(spi_bus_device_t *bus, const spi_txn_segment_t *segs, const uint32_t count) {
-  spi_txn_wait(bus);
+void spi_seg_transfer_start(spi_bus_device_t *bus) {
+  const spi_ports_t port = bus->port;
 
+  spi_txn_wait(bus);
   while (!spi_txn_can_send(bus, false))
     ;
 
-  const spi_ports_t port = bus->port;
-
   spi_dev[port].dma_done = false;
 
   spi_reconfigure(bus);
 
   spi_csn_enable(bus);
-#if defined(STM32H7)
-  uint32_t transfer_size = 0;
-  for (uint32_t i = 0; i < count; i++) {
-    transfer_size += segs[i].size;
-  }
-  LL_SPI_SetTransferSize(spi_port_defs[port].channel, transfer_size);
-  LL_SPI_Enable(spi_port_defs[port].channel);
-  LL_SPI_StartMasterTransfer(spi_port_defs[port].channel);
-#else
+#if !defined(STM32H7)
   LL_SPI_Enable(spi_port_defs[port].channel);
 #endif
+}
 
-  for (uint32_t i = 0; i < count; i++) {
-    const spi_txn_segment_t *seg = &segs[i];
-    const uint32_t size = seg->size;
-
-    const uint8_t *tx_data = NULL;
-    uint8_t *rx_data = NULL;
+void spi_seg_transfer_bytes(spi_bus_device_t *bus, const uint8_t *tx_data, uint8_t *rx_data, const uint32_t size) {
+  const spi_ports_t port = bus->port;
 
-    if (seg->type == TXN_CONST) {
-      tx_data = seg->bytes;
-    } else {
-      tx_data = seg->tx_data;
-      rx_data = seg->rx_data;
-    }
+#if defined(STM32H7)
+  LL_SPI_SetTransferSize(spi_port_defs[port].channel, size);
+  LL_SPI_Enable(spi_port_defs[port].channel);
+  LL_SPI_StartMasterTransfer(spi_port_defs[port].channel);
+#endif
 
-    for (uint32_t j = 0; j < size; j++) {
+  for (uint32_t i = 0; i < size; i++) {
 #if defined(STM32H7)
-      while (!LL_SPI_IsActiveFlag_TXP(spi_port_defs[port].channel))
-        ;
+    while (!LL_SPI_IsActiveFlag_TXP(spi_port_defs[port].channel))
+      ;
 #else
-      while (!LL_SPI_IsActiveFlag_TXE(spi_port_defs[port].channel))
-        ;
+    while (!LL_SPI_IsActiveFlag_TXE(spi_port_defs[port].channel))
+      ;
 #endif
-      LL_SPI_TransmitData8(spi_port_defs[port].channel, tx_data ? tx_data[j] : 0xFF);
+    LL_SPI_TransmitData8(spi_port_defs[port].channel, tx_data ? tx_data[i] : 0xFF);
 #if defined(STM32H7)
-      while (!LL_SPI_IsActiveFlag_RXP(spi_port_defs[port].channel))
-        ;
+    while (!LL_SPI_IsActiveFlag_RXP(spi_port_defs[port].channel))
+      ;
 #else
-      while (!LL_SPI_IsActiveFlag_RXNE(spi_port_defs[port].channel))
-        ;
+    while (!LL_SPI_IsActiveFlag_RXNE(spi_port_defs[port].channel))
+      ;
 #endif
-      const uint8_t ret = LL_SPI_ReceiveData8(spi_port_defs[port].channel);
-      if (rx_data != NULL) {
-        rx_data[j] = ret;
-      }
-    }
+    const uint8_t ret = LL_SPI_ReceiveData8(spi_port_defs[port].channel);
+    if (rx_data)
+      rx_data[i] = ret;
   }
 
 #if defined(STM32H7)
   while (!LL_SPI_IsActiveFlag_EOT(spi_port_defs[port].channel))
     ;
-
   LL_SPI_ClearFlag_TXTF(spi_port_defs[port].channel);
   LL_SPI_Disable(spi_port_defs[port].channel);
-#else
+#endif
+}
+
+void spi_seg_transfer_finish(spi_bus_device_t *bus) {
+  const spi_ports_t port = bus->port;
+
+#if !defined(STM32H7)
   LL_SPI_Disable(spi_port_defs[port].channel);
 #endif
   spi_csn_disable(bus);
diff --git a/src/driver/osd/max7456.c b/src/driver/osd/max7456.c
index e4c506563..ac4ee7b5d 100644
--- a/src/driver/osd/max7456.c
+++ b/src/driver/osd/max7456.c
@@ -41,24 +41,19 @@ static uint8_t max7456_dma_spi_read(uint8_t reg) {
   spi_bus_device_reconfigure(&bus, SPI_MODE_LEADING_EDGE, MAX7456_BAUD_RATE);
 
   uint8_t ret = 0;
-
-  const spi_txn_segment_t segs[] = {
-      spi_make_seg_const(reg),
-      spi_make_seg_buffer(&ret, NULL, 1),
-  };
-  spi_seg_submit_wait(&bus, segs);
-
+  spi_seg_submit_wait(&bus, {
+    spi_make_seg_const(reg);
+    spi_make_seg_buffer(&ret, NULL, 1);
+  });
   return ret;
 }
 
 // blocking dma write of a single register
 static void max7456_dma_spi_write(uint8_t reg, uint8_t data) {
   spi_bus_device_reconfigure(&bus, SPI_MODE_LEADING_EDGE, MAX7456_BAUD_RATE);
-
-  const spi_txn_segment_t segs[] = {
-      spi_make_seg_const(reg, data),
-  };
-  spi_seg_submit_wait(&bus, segs);
+  spi_seg_submit_wait(&bus, {
+    spi_make_seg_const(reg, data);
+  });
 }
 
 static bool max7456_init_display() {
@@ -131,15 +126,11 @@ static void max7456_set_system(osd_system_t sys) {
 
 static osd_system_t max7456_current_system() {
   static uint8_t stat = 0;
-
-  const spi_txn_segment_t segs[] = {
-      spi_make_seg_const(STAT),
-      spi_make_seg_buffer(&stat, NULL, 1),
-  };
-  const bool is_done = spi_seg_submit_check(&bus, segs, {
+  const bool is_done = spi_seg_submit_check(&bus, {
+      spi_make_seg_const(STAT);
+      spi_make_seg_buffer(&stat, NULL, 1); }, {
     spi_bus_device_reconfigure(&bus, SPI_MODE_LEADING_EDGE, MAX7456_BAUD_RATE);
-    stat = 0;
-  });
+    stat = 0; });
   if (!is_done) {
     return last_osd_system;
   }
@@ -240,31 +231,23 @@ bool max7456_push_string(uint8_t attr, uint8_t x, uint8_t y, const uint8_t *data
 
   spi_bus_device_reconfigure(&bus, SPI_MODE_LEADING_EDGE, MAX7456_BAUD_RATE);
 
-  uint32_t offset = 0;
-  uint8_t buf[8 + size * 2];
-
-  buf[offset++] = DMM;
-  buf[offset++] = max7456_map_attr(attr);
-
-  const uint16_t pos = x + y * MAX7456_COLS;
-  buf[offset++] = DMAH;
-  buf[offset++] = (pos >> 8) & 0xFF;
-  buf[offset++] = DMAL;
-  buf[offset++] = pos & 0xFF;
-
+  uint8_t buf[size * 2];
   for (uint8_t i = 0; i < size; i++) {
-    buf[offset++] = DMDI;
-    buf[offset++] = data[i];
+    buf[i * 2 + 0] = DMDI;
+    buf[i * 2 + 1] = data[i];
   }
 
-  // off autoincrement mode
-  buf[offset++] = DMDI;
-  buf[offset++] = 0xFF;
-
-  const spi_txn_segment_t segs[] = {
-      spi_make_seg_buffer(NULL, buf, offset),
-  };
-  spi_seg_submit_continue(&bus, segs);
+  const uint16_t pos = x + y * MAX7456_COLS;
+  spi_seg_submit(&bus, {
+    spi_make_seg_const(
+        DMM,
+        max7456_map_attr(attr),
+        DMAH, (pos >> 8) & 0xFF,
+        DMAL, pos & 0xFF);
+    spi_make_seg_buffer(NULL, buf, size * 2);
+    spi_make_seg_const(DMDI, 0xFF); // off autoincrement mode
+  });
+  spi_txn_continue(&bus);
 
   return true;
 }
diff --git a/src/driver/rx/a7105.c b/src/driver/rx/a7105.c
index 4407444f4..f96b9d49f 100644
--- a/src/driver/rx/a7105.c
+++ b/src/driver/rx/a7105.c
@@ -23,38 +23,33 @@ void a7105_handle_exti(bool pin_state) {
 }
 
 void a7105_write_reg(a7105_reg_t reg, uint8_t data) {
-  const spi_txn_segment_t segs[] = {
-      spi_make_seg_const(reg, data),
-  };
-  spi_seg_submit_continue(&bus, segs);
+  spi_seg_submit(&bus, {
+    spi_make_seg_const(reg, data);
+  });
+  spi_txn_continue(&bus);
 }
 
 static void a7105_write_multi(uint8_t reg, const uint8_t *data, uint8_t len) {
-  const spi_txn_segment_t segs[] = {
-      spi_make_seg_const(reg),
-      spi_make_seg_buffer(NULL, data, len),
-  };
-  spi_seg_submit_wait(&bus, segs);
+  spi_seg_submit_wait(&bus, {
+    spi_make_seg_const(reg);
+    spi_make_seg_buffer(NULL, data, len);
+  });
 }
 
 uint8_t a7105_read_reg(a7105_reg_t reg) {
   uint8_t ret = 0;
-
-  const spi_txn_segment_t segs[] = {
-      spi_make_seg_const(reg | 0x40),
-      spi_make_seg_buffer(&ret, NULL, 1),
-  };
-  spi_seg_submit_wait(&bus, segs);
-
+  spi_seg_submit_wait(&bus, {
+    spi_make_seg_const(reg | 0x40);
+    spi_make_seg_buffer(&ret, NULL, 1);
+  });
   return ret;
 }
 
 static void a7105_read_multi(uint8_t reg, uint8_t *result, uint8_t len) {
-  const spi_txn_segment_t segs[] = {
-      spi_make_seg_const(reg),
-      spi_make_seg_buffer(result, NULL, len),
-  };
-  spi_seg_submit_wait(&bus, segs);
+  spi_seg_submit_wait(&bus, {
+    spi_make_seg_const(reg);
+    spi_make_seg_buffer(result, NULL, len);
+  });
 }
 
 void a7105_strobe(a7105_strobe_t address) {
@@ -66,10 +61,10 @@ void a7105_strobe(a7105_strobe_t address) {
     exti_interrupt_disable(target.rx_spi.exti);
   }
 
-  const spi_txn_segment_t segs[] = {
-      spi_make_seg_const(address),
-  };
-  spi_seg_submit_continue(&bus, segs);
+  spi_seg_submit(&bus, {
+    spi_make_seg_const(address);
+  });
+  spi_txn_continue(&bus);
 }
 
 void a7105_read_fifo(uint8_t *data, uint8_t num) {
diff --git a/src/driver/rx/cc2500.c b/src/driver/rx/cc2500.c
index 8080b4dc4..2deb3b5b8 100644
--- a/src/driver/rx/cc2500.c
+++ b/src/driver/rx/cc2500.c
@@ -75,10 +75,10 @@ uint8_t cc2500_read_gdo0() {
 }
 
 void cc2500_strobe(uint8_t address) {
-  const spi_txn_segment_t segs[] = {
-      spi_make_seg_const(address),
-  };
-  spi_seg_submit_continue(&bus, segs);
+  spi_seg_submit(&bus, {
+    spi_make_seg_const(address);
+  });
+  spi_txn_continue(&bus);
 }
 
 void cc2500_strobe_sync(uint8_t address) {
@@ -88,72 +88,54 @@ void cc2500_strobe_sync(uint8_t address) {
 
 uint8_t cc2500_get_status() {
   uint8_t status = 0;
-
-  const spi_txn_segment_t segs[] = {
-      spi_make_seg_buffer(&status, NULL, 1),
-  };
-  spi_seg_submit_wait(&bus, segs);
-
+  spi_seg_submit_wait(&bus, {
+    spi_make_seg_buffer(&status, NULL, 1);
+  });
   return status;
 }
 
 void cc2500_write_reg(uint8_t reg, uint8_t data) {
-  const spi_txn_segment_t segs[] = {
-      spi_make_seg_const(reg | CC2500_WRITE_SINGLE, data),
-  };
-  spi_seg_submit_continue(&bus, segs);
+  spi_seg_submit(&bus, {
+    spi_make_seg_const(reg | CC2500_WRITE_SINGLE, data);
+  });
+  spi_txn_continue(&bus);
 }
 
 uint8_t cc2500_read_reg(uint8_t reg) {
   uint8_t ret = 0;
-
-  const spi_txn_segment_t segs[] = {
-      spi_make_seg_const(reg | CC2500_READ_SINGLE),
-      spi_make_seg_buffer(&ret, NULL, 1),
-  };
-  spi_seg_submit_wait(&bus, segs);
-
+  spi_seg_submit_wait(&bus, {
+    spi_make_seg_const(reg | CC2500_READ_SINGLE);
+    spi_make_seg_buffer(&ret, NULL, 1);
+  });
   return ret;
 }
 
 static uint8_t cc2500_read_multi(uint8_t reg, uint8_t *result, uint8_t len) {
-  const spi_txn_segment_t segs[] = {
-      spi_make_seg_buffer(&reg, &reg, 1),
-      spi_make_seg_buffer(result, NULL, len),
-  };
-  spi_seg_submit_wait(&bus, segs);
-
+  spi_seg_submit_wait(&bus, {
+    spi_make_seg_buffer(&reg, &reg, 1);
+    spi_make_seg_buffer(result, NULL, len);
+  });
   return reg;
 }
 
 static void cc2500_write_multi(uint8_t reg, uint8_t *data, uint8_t len) {
-  const spi_txn_segment_t segs[] = {
-      spi_make_seg_const(reg),
-      spi_make_seg_buffer(NULL, data, len),
-  };
-  spi_seg_submit_wait(&bus, segs);
+  spi_seg_submit_wait(&bus, {
+    spi_make_seg_const(reg);
+    spi_make_seg_buffer(NULL, data, len);
+  });
 }
 
 void cc2500_set_channel(uint8_t channel, uint8_t *cal_data) {
-  {
-    const spi_txn_segment_t segs[] = {
-        spi_make_seg_const(CC2500_SIDLE),
-    };
-    spi_seg_submit(&bus, segs);
-  }
-  {
-    const spi_txn_segment_t segs[] = {
-        spi_make_seg_const(CC2500_FSCAL3 | CC2500_WRITE_BURST),
-        spi_make_seg_buffer(NULL, cal_data, 3),
-    };
-    spi_seg_submit(&bus, segs);
-  }
-  {
-    const spi_txn_segment_t segs[] = {
-        spi_make_seg_const(CC2500_CHANNR | CC2500_WRITE_SINGLE, channel),
-    };
-    spi_seg_submit(&bus, segs);
-  }
+  spi_seg_submit(&bus, {
+    spi_make_seg_const(CC2500_SIDLE);
+  });
+  spi_seg_submit(&bus, {
+    spi_make_seg_const(CC2500_FSCAL3 | CC2500_WRITE_BURST);
+    spi_make_seg_buffer(NULL, cal_data, 3);
+  });
+  spi_seg_submit(&bus, {
+    spi_make_seg_const(CC2500_CHANNR | CC2500_WRITE_SINGLE, channel);
+  });
   spi_txn_continue(&bus);
 }
 
@@ -171,15 +153,12 @@ uint8_t cc2500_packet_size() {
     uint8_t len1 = 0;
     uint8_t len2 = 0;
 
-    {
-      const spi_txn_segment_t segs[] = {
-          spi_make_seg_const(CC2500_RXBYTES | CC2500_READ_SINGLE),
-          spi_make_seg_buffer(&len1, NULL, 1),
-          spi_make_seg_const(CC2500_RXBYTES | CC2500_READ_SINGLE),
-          spi_make_seg_buffer(&len2, NULL, 1),
-      };
-      spi_seg_submit_wait(&bus, segs);
-    }
+    spi_seg_submit_wait(&bus, {
+      spi_make_seg_const(CC2500_RXBYTES | CC2500_READ_SINGLE);
+      spi_make_seg_buffer(&len1, NULL, 1);
+      spi_make_seg_const(CC2500_RXBYTES | CC2500_READ_SINGLE);
+      spi_make_seg_buffer(&len2, NULL, 1);
+    });
 
     // valid len found?
     if (len1 == len2) {
diff --git a/src/driver/rx/sx128x.c b/src/driver/rx/sx128x.c
index 7efd04661..fd0afdcb9 100644
--- a/src/driver/rx/sx128x.c
+++ b/src/driver/rx/sx128x.c
@@ -100,8 +100,7 @@ static bool sx128x_poll_for_not_busy() {
   return true;
 }
 
-#define read_command_txn(cmd, data, size) \
-  spi_make_seg_const(cmd, 0x0), spi_make_seg_buffer(data, NULL, size)
+#define read_command_txn(cmd, data, size)
 
 static void sx128x_set_dio0_active(void *arg) {
   packet_time_us = time_micros();
@@ -109,28 +108,21 @@ static void sx128x_set_dio0_active(void *arg) {
 }
 
 static void sx128x_read_buffer(void *arg) {
-  {
-    const spi_txn_segment_t segs[] = {
-        spi_make_seg_const(SX1280_RADIO_READ_BUFFER, buffer_status[1], 0x00),
-        spi_make_seg_buffer((uint8_t *)rx_spi_packet, NULL, payload_len),
-    };
-    spi_seg_submit(&bus, segs);
-  }
-  {
-    const spi_txn_segment_t segs[] = {
-        read_command_txn(SX1280_RADIO_GET_PACKETSTATUS, (uint8_t *)packet_status, 2),
-    };
-    spi_seg_submit(&bus, segs, .done_fn = sx128x_set_dio0_active);
-  }
+  spi_seg_submit(&bus, {
+    spi_make_seg_const(SX1280_RADIO_READ_BUFFER, buffer_status[1], 0x00);
+    spi_make_seg_buffer((uint8_t *)rx_spi_packet, NULL, payload_len);
+  });
+  spi_seg_submit(&bus, { 
+     spi_make_seg_const(SX1280_RADIO_GET_PACKETSTATUS, 0x0);
+     spi_make_seg_buffer((uint8_t *)packet_status, NULL, 2); }, .done_fn = sx128x_set_dio0_active);
 }
 
 static void sx128x_handle_irq_status(void *arg) {
   const uint16_t irq = ((irq_status & 0xFF) << 8 | ((irq_status >> 8) & 0xFF));
   if ((irq & SX1280_IRQ_RX_DONE)) {
-    const spi_txn_segment_t segs[] = {
-        read_command_txn(SX1280_RADIO_GET_RXBUFFERSTATUS, buffer_status, 2),
-    };
-    spi_seg_submit(&bus, segs, .done_fn = sx128x_read_buffer);
+    spi_seg_submit(&bus, { 
+     spi_make_seg_const(SX1280_RADIO_GET_RXBUFFERSTATUS, 0x0);
+     spi_make_seg_buffer(buffer_status, NULL, 2); }, .done_fn = sx128x_read_buffer);
   } else if ((irq & SX1280_IRQ_TX_DONE)) {
     sx128x_set_mode_async(SX1280_MODE_RX);
   }
@@ -158,21 +150,14 @@ void sx128x_handle_dio0_exti(bool level) {
   if (!level)
     return;
 
-  {
-    const spi_txn_segment_t segs[] = {
-        read_command_txn(SX1280_RADIO_GET_IRQSTATUS, (uint8_t *)&irq_status, 2),
-    };
-    spi_seg_submit(&bus, segs);
-  }
-  {
-    const spi_txn_segment_t segs[] = {
-        spi_make_seg_const(
-            SX1280_RADIO_CLR_IRQSTATUS,
-            (uint8_t)(((uint16_t)SX1280_IRQ_RADIO_ALL >> 8) & 0x00FF),
-            (uint8_t)((uint16_t)SX1280_IRQ_RADIO_ALL & 0x00FF)),
-    };
-    spi_seg_submit(&bus, segs, .done_fn = sx128x_handle_irq_status);
-  }
+  spi_seg_submit(&bus, {
+    spi_make_seg_const(SX1280_RADIO_GET_IRQSTATUS, 0x0);
+    spi_make_seg_buffer((uint8_t *)&irq_status, NULL, 2);
+  });
+  spi_seg_submit(&bus, { spi_make_seg_const(
+                             SX1280_RADIO_CLR_IRQSTATUS,
+                             (uint8_t)(((uint16_t)SX1280_IRQ_RADIO_ALL >> 8) & 0x00FF),
+                             (uint8_t)((uint16_t)SX1280_IRQ_RADIO_ALL & 0x00FF)); }, .done_fn = sx128x_handle_irq_status);
   spi_txn_continue(&bus);
 }
 
@@ -198,14 +183,13 @@ uint16_t sx128x_read_dio0() {
 }
 
 void sx128x_read_register_burst(const uint16_t reg, uint8_t *data, const uint8_t size) {
-  const spi_txn_segment_t segs[] = {
-      spi_make_seg_const((SX1280_RADIO_READ_REGISTER),
-                         ((reg & 0xFF00) >> 8),
-                         (reg & 0x00FF),
-                         0x00),
-      spi_make_seg_buffer(data, NULL, size),
-  };
-  spi_seg_submit(&bus, segs);
+  spi_seg_submit(&bus, {
+    spi_make_seg_const((SX1280_RADIO_READ_REGISTER),
+                       ((reg & 0xFF00) >> 8),
+                       (reg & 0x00FF),
+                       0x00);
+    spi_make_seg_buffer(data, NULL, size);
+  });
 }
 
 uint8_t sx128x_read_register(const uint16_t reg) {
@@ -216,13 +200,12 @@ uint8_t sx128x_read_register(const uint16_t reg) {
 }
 
 void sx128x_write_register_burst(const uint16_t reg, const uint8_t *data, const uint8_t size) {
-  const spi_txn_segment_t segs[] = {
-      spi_make_seg_const((uint8_t)SX1280_RADIO_WRITE_REGISTER,
-                         ((reg & 0xFF00) >> 8),
-                         (reg & 0x00FF)),
-      spi_make_seg_buffer(NULL, data, size),
-  };
-  spi_seg_submit(&bus, segs);
+  spi_seg_submit(&bus, {
+    spi_make_seg_const((uint8_t)SX1280_RADIO_WRITE_REGISTER,
+                       ((reg & 0xFF00) >> 8),
+                       (reg & 0x00FF));
+    spi_make_seg_buffer(NULL, data, size);
+  });
 }
 
 void sx128x_write_register(const uint16_t reg, const uint8_t val) {
@@ -230,18 +213,17 @@ void sx128x_write_register(const uint16_t reg, const uint8_t val) {
 }
 
 void sx128x_read_command_burst(const sx128x_commands_t cmd, uint8_t *data, const uint8_t size) {
-  const spi_txn_segment_t segs[] = {
-      read_command_txn(cmd, data, size),
-  };
-  spi_seg_submit(&bus, segs);
+  spi_seg_submit(&bus, {
+    spi_make_seg_const(cmd, 0x0);
+    spi_make_seg_buffer(data, NULL, size);
+  });
 }
 
 void sx128x_write_command_burst(const sx128x_commands_t cmd, const uint8_t *data, const uint8_t size) {
-  const spi_txn_segment_t segs[] = {
-      spi_make_seg_const(cmd),
-      spi_make_seg_buffer(NULL, data, size),
-  };
-  spi_seg_submit(&bus, segs);
+  spi_seg_submit(&bus, {
+    spi_make_seg_const(cmd);
+    spi_make_seg_buffer(NULL, data, size);
+  });
 }
 
 void sx128x_write_command(const sx128x_commands_t cmd, const uint8_t val) {
@@ -249,11 +231,10 @@ void sx128x_write_command(const sx128x_commands_t cmd, const uint8_t val) {
 }
 
 void sx128x_write_tx_buffer(const uint8_t offset, const volatile uint8_t *data, const uint8_t size) {
-  const spi_txn_segment_t segs[] = {
-      spi_make_seg_const(SX1280_RADIO_WRITE_BUFFER, offset),
-      spi_make_seg_buffer(NULL, (uint8_t *)data, size),
-  };
-  spi_seg_submit(&bus, segs);
+  spi_seg_submit(&bus, {
+    spi_make_seg_const(SX1280_RADIO_WRITE_BUFFER, offset);
+    spi_make_seg_buffer(NULL, (uint8_t *)data, size);
+  });
 }
 
 void sx128x_set_mode_async(const sx128x_modes_t mode) {
diff --git a/src/driver/spi.c b/src/driver/spi.c
index 655cae506..36d071823 100644
--- a/src/driver/spi.c
+++ b/src/driver/spi.c
@@ -18,20 +18,37 @@ extern void spi_device_init(spi_ports_t port);
 extern void spi_reconfigure(spi_bus_device_t *bus);
 extern void spi_dma_transfer_begin(spi_ports_t port, uint8_t *buffer, uint32_t length);
 
-static inline __attribute__((always_inline)) spi_txn_t *spi_txn_pop(spi_bus_device_t *bus) {
+spi_txn_t *spi_txn_pop(spi_bus_device_t *bus, const spi_txn_opts_t opt) {
   ATOMIC_BLOCK_ALL {
     for (uint32_t i = 0; i < SPI_TXN_MAX; i++) {
       if (txn_pool[i].status == TXN_IDLE) {
         spi_txn_t *txn = &txn_pool[i];
         txn->status = TXN_WAITING;
         txn->buffer = txn_buffers[i];
+        txn->bus = bus;
+        txn->size = 0;
+        txn->flags = 0;
+        txn->segment_count = 0;
+        txn->done_fn = opt.done_fn;
+        txn->done_fn_arg = opt.done_fn_arg;
         return txn;
       }
     }
   }
+  failloop(FAILLOOP_SPI);
   return NULL;
 }
 
+void spi_txn_push(spi_bus_device_t *bus, spi_txn_t *txn) {
+  ATOMIC_BLOCK_ALL {
+    spi_device_t *dev = &spi_dev[bus->port];
+    const uint8_t head = (dev->txn_head + 1) % SPI_TXN_MAX;
+    txn->status = TXN_READY;
+    dev->txns[head] = txn;
+    dev->txn_head = head;
+  }
+}
+
 bool spi_txn_can_send(spi_bus_device_t *bus, bool dma) {
   if (!spi_dma_is_ready(bus->port)) {
     return false;
@@ -89,58 +106,6 @@ bool spi_txn_continue_port(spi_ports_t port) {
   return true;
 }
 
-void spi_seg_submit_ex(spi_bus_device_t *bus, const spi_txn_opts_t opts) {
-  spi_txn_t *txn = spi_txn_pop(bus);
-  if (txn == NULL) {
-    failloop(FAILLOOP_SPI);
-  }
-
-  txn->bus = bus;
-  txn->size = 0;
-  txn->flags = 0;
-  txn->segment_count = opts.seg_count;
-  txn->done_fn = opts.done_fn;
-  txn->done_fn_arg = opts.done_fn_arg;
-
-  for (uint32_t i = 0; i < opts.seg_count; i++) {
-    const spi_txn_segment_t *seg = &opts.segs[i];
-    spi_txn_segment_t *txn_seg = &txn->segments[i];
-
-    switch (seg->type) {
-    case TXN_CONST:
-      txn_seg->rx_data = NULL;
-      txn_seg->tx_data = NULL;
-      memcpy(txn->buffer + txn->size, seg->bytes, seg->size);
-      break;
-
-    case TXN_BUFFER:
-      txn_seg->tx_data = NULL;
-      txn_seg->rx_data = seg->rx_data;
-      if (seg->tx_data) {
-        memcpy(txn->buffer + txn->size, seg->tx_data, seg->size);
-      } else {
-        memset(txn->buffer + txn->size, 0xFF, seg->size);
-      }
-      break;
-    }
-
-    if (txn_seg->rx_data) {
-      txn->flags |= TXN_DELAYED_RX;
-    }
-
-    txn_seg->size = seg->size;
-    txn->size += seg->size;
-  }
-
-  ATOMIC_BLOCK_ALL {
-    spi_device_t *dev = &spi_dev[bus->port];
-    const uint8_t head = (dev->txn_head + 1) % SPI_TXN_MAX;
-    txn->status = TXN_READY;
-    dev->txns[head] = txn;
-    dev->txn_head = head;
-  }
-}
-
 // only called from dma isr
 void spi_txn_finish(spi_ports_t port) {
   spi_device_t *dev = &spi_dev[port];
diff --git a/src/driver/spi.h b/src/driver/spi.h
index b35ea6a79..c01f6a1eb 100644
--- a/src/driver/spi.h
+++ b/src/driver/spi.h
@@ -2,10 +2,12 @@
 
 #include <stdbool.h>
 #include <stdint.h>
+#include <string.h>
 
 #include "core/project.h"
 #include "driver/dma.h"
 #include "driver/gpio.h"
+#include "driver/interrupt.h"
 #include "driver/rcc.h"
 
 typedef enum {
@@ -25,30 +27,11 @@ typedef struct {
 #define SPI_TXN_MAX 32
 #define SPI_TXN_SEG_MAX 8
 
-typedef enum {
-  TXN_CONST,
-  TXN_BUFFER,
-} spi_txn_segment_type_t;
-
 typedef struct {
-  spi_txn_segment_type_t type;
-  union {
-    struct {
-      uint8_t bytes[8];
-    };
-    struct {
-      const uint8_t *tx_data;
-      uint8_t *rx_data;
-    };
-  };
+  uint8_t *rx_data;
   uint32_t size;
 } spi_txn_segment_t;
 
-#define spi_make_seg_const(_bytes...) \
-  (spi_txn_segment_t) { .type = TXN_CONST, .bytes = {_bytes}, .size = sizeof((uint8_t[]){_bytes}) }
-#define spi_make_seg_buffer(_rx_data, _tx_data, _size) \
-  (spi_txn_segment_t) { .type = TXN_BUFFER, .rx_data = (_rx_data), .tx_data = (_tx_data), .size = (_size) }
-
 struct spi_bus_device;
 
 typedef enum {
@@ -83,9 +66,6 @@ typedef struct {
 typedef struct {
   spi_txn_done_fn_t done_fn;
   void *done_fn_arg;
-
-  const spi_txn_segment_t *segs;
-  uint32_t seg_count;
 } spi_txn_opts_t;
 
 typedef struct spi_bus_device {
@@ -119,66 +99,88 @@ extern const spi_port_def_t spi_port_defs[SPI_PORT_MAX];
 void spi_bus_device_init(const spi_bus_device_t *bus);
 
 void spi_txn_wait(spi_bus_device_t *bus);
+spi_txn_t *spi_txn_pop(spi_bus_device_t *bus, const spi_txn_opts_t opt);
+void spi_txn_push(spi_bus_device_t *bus, spi_txn_t *txn);
 bool spi_txn_continue_port(spi_ports_t port);
 
-void spi_seg_submit_ex(spi_bus_device_t *bus, const spi_txn_opts_t opts);
-void spi_seg_submit_wait_ex(spi_bus_device_t *bus, const spi_txn_segment_t *segs, const uint32_t count);
+void spi_seg_transfer_start(spi_bus_device_t *bus);
+void spi_seg_transfer_bytes(spi_bus_device_t *bus, const uint8_t *tx_data, uint8_t *rx_data, const uint32_t size);
+void spi_seg_transfer_finish(spi_bus_device_t *bus);
 
 static inline void spi_csn_enable(spi_bus_device_t *bus) { gpio_pin_reset(bus->nss); }
 static inline void spi_csn_disable(spi_bus_device_t *bus) { gpio_pin_set(bus->nss); }
 
+static inline bool spi_dma_is_ready(spi_ports_t port) { return spi_dev[port].dma_done; }
+static inline bool spi_txn_ready(spi_bus_device_t *bus) { return spi_dev[bus->port].txn_head == spi_dev[bus->port].txn_tail; }
+
 static inline bool spi_txn_continue(spi_bus_device_t *bus) { return spi_txn_continue_port(bus->port); }
+static inline void spi_txn_add_seg(spi_txn_t *txn, const uint8_t *tx_data, uint8_t *rx_data, const uint32_t size) {
+  spi_txn_segment_t *seg = &txn->segments[txn->segment_count];
+  seg->rx_data = rx_data;
+  if (seg->rx_data)
+    txn->flags |= TXN_DELAYED_RX;
 
-static inline void spi_bus_device_reconfigure(spi_bus_device_t *bus, spi_mode_t mode, uint32_t hz) {
-  bus->mode = mode;
-  bus->hz = hz;
-}
+  for (uint32_t i = 0; i < size; i++)
+    txn->buffer[txn->size + i] = tx_data ? tx_data[i] : 0xFF;
 
-static inline bool spi_dma_is_ready(spi_ports_t port) {
-  const spi_device_t *dev = &spi_dev[port];
-  return dev->dma_done;
+  txn->size += (seg->size = size);
+  txn->segment_count++;
 }
 
-static inline bool spi_txn_ready(spi_bus_device_t *bus) {
-  const spi_device_t *dev = &spi_dev[bus->port];
-  return dev->txn_head == dev->txn_tail;
+static inline void spi_bus_device_reconfigure(spi_bus_device_t *bus, spi_mode_t mode, uint32_t hz) {
+  bus->mode = mode;
+  bus->hz = hz;
 }
 
-#define spi_seg_submit_wait(_bus, _segs)                                                                            \
-  {                                                                                                                 \
-    static_assert(__builtin_types_compatible_p(spi_txn_segment_t[], typeof(_segs)), "spi segment not const array"); \
-    const uint32_t count = sizeof(_segs) / sizeof(spi_txn_segment_t);                                               \
-    static_assert(count < SPI_TXN_SEG_MAX, "spi segment count > max");                                              \
-    spi_seg_submit_wait_ex(_bus, _segs, count);                                                                     \
+#define spi_make_seg_buffer(_rx_data, _tx_data, _size)            \
+  {                                                               \
+    if (__is_async__)                                             \
+      spi_txn_add_seg(txn, _tx_data, _rx_data, _size);            \
+    else                                                          \
+      spi_seg_transfer_bytes(__bus__, _tx_data, _rx_data, _size); \
+  }
+#define spi_make_seg_const(_bytes...)               \
+  {                                                 \
+    const uint8_t __bytes__[] = {_bytes};           \
+    const uint32_t __size__ = sizeof(__bytes__);    \
+    spi_make_seg_buffer(NULL, __bytes__, __size__); \
+  }
+#define spi_seg_submit_wait(_bus, _segs) \
+  {                                      \
+    const bool __is_async__ = false;     \
+    spi_bus_device_t *__bus__ = _bus;    \
+    spi_txn_t *txn = NULL;               \
+    spi_seg_transfer_start(__bus__);     \
+    _segs;                               \
+    spi_seg_transfer_finish(__bus__);    \
   }
-#define spi_seg_submit(_bus, _segs, ...)                                                                            \
-  {                                                                                                                 \
-    static_assert(__builtin_types_compatible_p(spi_txn_segment_t[], typeof(_segs)), "spi segment not const array"); \
-    const uint32_t count = sizeof(_segs) / sizeof(spi_txn_segment_t);                                               \
-    static_assert(count < SPI_TXN_SEG_MAX, "spi segment count > max");                                              \
-    spi_seg_submit_ex(_bus, (spi_txn_opts_t){.segs = _segs, .seg_count = count, __VA_ARGS__});                      \
+#define spi_seg_submit(_bus, _segs, _opts...)        \
+  {                                                  \
+    const bool __is_async__ = true;                  \
+    spi_bus_device_t *__bus__ = _bus;                \
+    const spi_txn_opts_t __opts__ = {_opts};         \
+    spi_txn_t *txn = spi_txn_pop(__bus__, __opts__); \
+    _segs;                                           \
+    spi_txn_push(__bus__, txn);                      \
   }
-#define spi_seg_submit_continue(_bus, _segs, ...) ({ \
-  spi_seg_submit(_bus, _segs, __VA_ARGS__);          \
-  spi_txn_continue(_bus);                            \
-})
 
 static inline void spi_txn_set_done(void *arg) { *((bool *)arg) = true; }
-#define spi_seg_submit_check(_bus, _segs, ...)                      \
-  ({                                                                \
-    static volatile bool __did_submit__ = false;                    \
-    static volatile bool __is_done__ = false;                       \
-    if (!__did_submit__) {                                          \
-      __VA_ARGS__;                                                  \
-      spi_seg_submit_continue(_bus, _segs,                          \
-                              .done_fn = spi_txn_set_done,          \
-                              .done_fn_arg = (void *)&__is_done__); \
-      __did_submit__ = true;                                        \
-    }                                                               \
-    const bool temp = __is_done__;                                  \
-    if (__is_done__) {                                              \
-      __did_submit__ = false;                                       \
-      __is_done__ = false;                                          \
-    }                                                               \
-    temp;                                                           \
+#define spi_seg_submit_check(_bus, _segs, ...)             \
+  ({                                                       \
+    static volatile bool __did_submit__ = false;           \
+    static volatile bool __is_done__ = false;              \
+    if (!__did_submit__) {                                 \
+      __VA_ARGS__;                                         \
+      spi_seg_submit(_bus, _segs,                          \
+                     .done_fn = spi_txn_set_done,          \
+                     .done_fn_arg = (void *)&__is_done__); \
+      spi_txn_continue(_bus);                              \
+      __did_submit__ = true;                               \
+    }                                                      \
+    const bool temp = __is_done__;                         \
+    if (__is_done__) {                                     \
+      __did_submit__ = false;                              \
+      __is_done__ = false;                                 \
+    }                                                      \
+    temp;                                                  \
   })