From e9884c31943c2b6300224a8597b478980d7bb070 Mon Sep 17 00:00:00 2001
From: Frederic Pillon <frederic.pillon@st.com>
Date: Tue, 18 Aug 2026 16:40:39 +0200
Subject: [PATCH] fix(spi): init never called at begin

Regression introduced during ArduinoCore-API deployment.
(_spiSettings != settings) conditions always false by default
(if busMode not changed).
The only way to get SPI functional was to call begin_transaction
with a different settings else error handler is called.

Signed-off-by: Frederic Pillon <frederic.pillon@st.com>
---
 libraries/SPI/src/SPI.cpp | 35 ++++++++---------------------------
 libraries/SPI/src/SPI.h   |  2 --
 2 files changed, 8 insertions(+), 29 deletions(-)

diff --git a/libraries/SPI/src/SPI.cpp b/libraries/SPI/src/SPI.cpp
index 2a23c0ef31..6515471f57 100644
--- a/libraries/SPI/src/SPI.cpp
+++ b/libraries/SPI/src/SPI.cpp
@@ -13,25 +13,6 @@
 
 SPIClass SPI;
 
-void SPIClass::configSpi(const SPISettings &settings)
-{
-  if (_spiSettings != settings) {
-    _spiSettings = settings;
-
-    uint32_t  clock   = settings.getClockFreq();
-    SPIMode   dataMode    = settings.getDataMode();
-    BitOrder  order   = settings.getBitOrder();
-    SPIBusMode busMode    = settings.getBusMode();
-
-    // Mapping API dataMode → spi_mode_e C
-    spi_mode_e cspimode = static_cast<spi_mode_e>(dataMode);
-    // Mapping API busMode → spi_busmode_e C
-    spi_busmode_e cbusmode = static_cast<spi_busmode_e>(busMode);
-
-    spi_init(&_spi, clock, cspimode, order, cbusmode);
-  }
-}
-
 /**
   * @brief  Default Constructor. Uses pin configuration of default SPI
   *         defined in the variant*.h.
@@ -73,13 +54,9 @@ void SPIClass::begin(SPIBusMode busMode)
   _spi.handle.State = HAL_SPI_STATE_RESET;
 #endif
 
-  SPISettings defaultSettings(
-    SPI_SPEED_CLOCK_DEFAULT, // 4 MHz
-    MSBFIRST,
-    SPI_MODE0,
-    busMode
-  );
-  configSpi(defaultSettings);
+  _spiSettings = SPISettings(4000000, MSBFIRST, SPI_MODE0, busMode);
+  spi_init(&_spi, _spiSettings.getClockFreq(), (spi_mode_e)_spiSettings.getDataMode(),
+           _spiSettings.getBitOrder(), (spi_busmode_e)_spiSettings.getBusMode());
 }
 
 /**
@@ -89,7 +66,11 @@ void SPIClass::begin(SPIBusMode busMode)
   */
 void SPIClass::beginTransaction(SPISettings settings)
 {
-  configSpi(settings);
+  if (_spiSettings != settings) {
+    _spiSettings = settings;
+    spi_init(&_spi, _spiSettings.getClockFreq(), (spi_mode_e)_spiSettings.getDataMode(),
+             _spiSettings.getBitOrder(), (spi_busmode_e)_spiSettings.getBusMode());
+  }
 }
 
 /**
diff --git a/libraries/SPI/src/SPI.h b/libraries/SPI/src/SPI.h
index 0560a0b7f0..2f04e65196 100644
--- a/libraries/SPI/src/SPI.h
+++ b/libraries/SPI/src/SPI.h
@@ -134,8 +134,6 @@ class SPIClass : public HardwareSPI {
   private:
     /* Current SPISettings */
     SPISettings   _spiSettings = SPISettings();
-
-    void configSpi(const SPISettings &settings);
 };
 
 extern SPIClass SPI;