diff mbox series

spi: stm32: Revert change that enabled controller before asserting CS

Message ID 20240523103326.792907-2-u.kleine-koenig@pengutronix.de
State Accepted
Commit a827ad9b3c2fc243e058595533f91ce41a312527
Headers show
Series spi: stm32: Revert change that enabled controller before asserting CS | expand

Commit Message

Uwe Kleine-König May 23, 2024, 10:33 a.m. UTC
On stm32mp157 enabling the controller before asserting CS makes the
hardware trigger spurious interrupts in a tight loop and the transfers
fail. Revert the commit that swapped the order of enable and CS. This
reintroduces the problem that swapping was supposed to fix, which
however is less grave.

Reported-by: Leonard Göhrs <l.goehrs@pengutronix.de>
Link: https://lore.kernel.org/all/39033ed7-3e57-4339-80b4-fc8919e26aa7@pengutronix.de/
Fixes: 52b62e7a5d4f ("spi: stm32: enable controller before asserting CS")
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
---
 drivers/spi/spi-stm32.c | 14 ++++++++++++--
 1 file changed, 12 insertions(+), 2 deletions(-)


base-commit: a38297e3fb012ddfa7ce0321a7e5a8daeb1872b6
diff mbox series

Patch

diff --git a/drivers/spi/spi-stm32.c b/drivers/spi/spi-stm32.c
index 4a68abcdcc35..e4e7ddb7524a 100644
--- a/drivers/spi/spi-stm32.c
+++ b/drivers/spi/spi-stm32.c
@@ -1016,8 +1016,10 @@  static irqreturn_t stm32fx_spi_irq_event(int irq, void *dev_id)
 static irqreturn_t stm32fx_spi_irq_thread(int irq, void *dev_id)
 {
 	struct spi_controller *ctrl = dev_id;
+	struct stm32_spi *spi = spi_controller_get_devdata(ctrl);
 
 	spi_finalize_current_transfer(ctrl);
+	stm32fx_spi_disable(spi);
 
 	return IRQ_HANDLED;
 }
@@ -1185,8 +1187,6 @@  static int stm32_spi_prepare_msg(struct spi_controller *ctrl,
 			 ~clrb) | setb,
 			spi->base + spi->cfg->regs->cpol.reg);
 
-	stm32_spi_enable(spi);
-
 	spin_unlock_irqrestore(&spi->lock, flags);
 
 	return 0;
@@ -1204,6 +1204,7 @@  static void stm32fx_spi_dma_tx_cb(void *data)
 
 	if (spi->cur_comm == SPI_SIMPLEX_TX || spi->cur_comm == SPI_3WIRE_TX) {
 		spi_finalize_current_transfer(spi->ctrl);
+		stm32fx_spi_disable(spi);
 	}
 }
 
@@ -1218,6 +1219,7 @@  static void stm32_spi_dma_rx_cb(void *data)
 	struct stm32_spi *spi = data;
 
 	spi_finalize_current_transfer(spi->ctrl);
+	spi->cfg->disable(spi);
 }
 
 /**
@@ -1305,6 +1307,8 @@  static int stm32fx_spi_transfer_one_irq(struct stm32_spi *spi)
 
 	stm32_spi_set_bits(spi, STM32FX_SPI_CR2, cr2);
 
+	stm32_spi_enable(spi);
+
 	/* starting data transfer when buffer is loaded */
 	if (spi->tx_buf)
 		spi->cfg->write_tx(spi);
@@ -1341,6 +1345,8 @@  static int stm32h7_spi_transfer_one_irq(struct stm32_spi *spi)
 
 	spin_lock_irqsave(&spi->lock, flags);
 
+	stm32_spi_enable(spi);
+
 	/* Be sure to have data in fifo before starting data transfer */
 	if (spi->tx_buf)
 		stm32h7_spi_write_txfifo(spi);
@@ -1372,6 +1378,8 @@  static void stm32fx_spi_transfer_one_dma_start(struct stm32_spi *spi)
 		 */
 		stm32_spi_set_bits(spi, STM32FX_SPI_CR2, STM32FX_SPI_CR2_ERRIE);
 	}
+
+	stm32_spi_enable(spi);
 }
 
 /**
@@ -1405,6 +1413,8 @@  static void stm32h7_spi_transfer_one_dma_start(struct stm32_spi *spi)
 
 	stm32_spi_set_bits(spi, STM32H7_SPI_IER, ier);
 
+	stm32_spi_enable(spi);
+
 	if (STM32_SPI_HOST_MODE(spi))
 		stm32_spi_set_bits(spi, STM32H7_SPI_CR1, STM32H7_SPI_CR1_CSTART);
 }