From 4cbe4df46b7ebc43a6d40cc38b2d04e80a10aaa3 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Uwe=20Kleine-K=C3=B6nig?= Date: Thu, 23 May 2024 12:33:25 +0200 Subject: [PATCH] spi: stm32: Revert change that enabled controller before asserting CS MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit [ Upstream commit a827ad9b3c2fc243e058595533f91ce41a312527 ] 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 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 Link: https://msgid.link/r/20240523103326.792907-2-u.kleine-koenig@pengutronix.de Signed-off-by: Mark Brown Signed-off-by: Sasha Levin --- drivers/spi/spi-stm32.c | 14 ++++++++++++-- 1 file changed, 12 insertions(+), 2 deletions(-) diff --git a/drivers/spi/spi-stm32.c b/drivers/spi/spi-stm32.c index 4a68abcdcc3535..e4e7ddb7524a99 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); }