From 90b5c170347e7a46a8f56628a9830ea5a719a326 Mon Sep 17 00:00:00 2001
From: Copilot <198982749+Copilot@users.noreply.github.com>
Date: Sun, 6 Jul 2025 07:20:48 +0100
Subject: [PATCH] Fix SPI bus lock issue in spi_start_extended when using
 mutual exclusion (#25447)

---
 platforms/chibios/drivers/spi_master.c | 15 +++++++++++++++
 1 file changed, 15 insertions(+)

diff --git a/platforms/chibios/drivers/spi_master.c b/platforms/chibios/drivers/spi_master.c
index f5e48edfda5..84d027bf49d 100644
--- a/platforms/chibios/drivers/spi_master.c
+++ b/platforms/chibios/drivers/spi_master.c
@@ -130,10 +130,16 @@ bool spi_start_extended(spi_start_config_t *start_config) {
 #endif // (SPI_USE_MUTUAL_EXCLUSION == TRUE)
 
     if (spiStarted) {
+#if (SPI_USE_MUTUAL_EXCLUSION == TRUE)
+        spiReleaseBus(&SPI_DRIVER);
+#endif // (SPI_USE_MUTUAL_EXCLUSION == TRUE)
         return false;
     }
 #if SPI_SELECT_MODE != SPI_SELECT_MODE_NONE
     if (start_config->slave_pin == NO_PIN) {
+#    if (SPI_USE_MUTUAL_EXCLUSION == TRUE)
+        spiReleaseBus(&SPI_DRIVER);
+#    endif // (SPI_USE_MUTUAL_EXCLUSION == TRUE)
         return false;
     }
 #endif
@@ -146,10 +152,16 @@ bool spi_start_extended(spi_start_config_t *start_config) {
 
 #    if defined(AT32F415)
     if (roundedDivisor < 2 || roundedDivisor > 1024) {
+#        if (SPI_USE_MUTUAL_EXCLUSION == TRUE)
+        spiReleaseBus(&SPI_DRIVER);
+#        endif // (SPI_USE_MUTUAL_EXCLUSION == TRUE)
         return false;
     }
 #    else
     if (roundedDivisor < 2 || roundedDivisor > 256) {
+#        if (SPI_USE_MUTUAL_EXCLUSION == TRUE)
+        spiReleaseBus(&SPI_DRIVER);
+#        endif // (SPI_USE_MUTUAL_EXCLUSION == TRUE)
         return false;
     }
 #    endif
@@ -234,6 +246,9 @@ bool spi_start_extended(spi_start_config_t *start_config) {
     }
 
     if (start_config->divisor < 1) {
+#    if (SPI_USE_MUTUAL_EXCLUSION == TRUE)
+        spiReleaseBus(&SPI_DRIVER);
+#    endif // (SPI_USE_MUTUAL_EXCLUSION == TRUE)
         return false;
     }