From d356d3379d8782f0b6db324cd6e01e718ea8fe2e Mon Sep 17 00:00:00 2001 From: Alain Volmat Date: Mon, 9 Oct 2023 10:24:50 +0200 Subject: [PATCH] dmaengine: stm32-mdma: correct desc prep when channel running commit 03f25d53b145bc2f7ccc82fc04e4482ed734f524 upstream. In case of the prep descriptor while the channel is already running, the CCR register value stored into the channel could already have its EN bit set. This would lead to a bad transfer since, at start transfer time, enabling the channel while other registers aren't yet properly set. To avoid this, ensure to mask the CCR_EN bit when storing the ccr value into the mdma channel structure. Fixes: a4ffb13c8946 ("dmaengine: Add STM32 MDMA driver") Signed-off-by: Alain Volmat Signed-off-by: Amelie Delaunay Cc: stable@vger.kernel.org Tested-by: Alain Volmat Link: https://lore.kernel.org/r/20231009082450.452877-1-amelie.delaunay@foss.st.com Signed-off-by: Vinod Koul Signed-off-by: Greg Kroah-Hartman --- drivers/dma/stm32-mdma.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/dma/stm32-mdma.c b/drivers/dma/stm32-mdma.c index bae08b3..f414efd 100644 --- a/drivers/dma/stm32-mdma.c +++ b/drivers/dma/stm32-mdma.c @@ -489,7 +489,7 @@ static int stm32_mdma_set_xfer_param(struct stm32_mdma_chan *chan, src_maxburst = chan->dma_config.src_maxburst; dst_maxburst = chan->dma_config.dst_maxburst; - ccr = stm32_mdma_read(dmadev, STM32_MDMA_CCR(chan->id)); + ccr = stm32_mdma_read(dmadev, STM32_MDMA_CCR(chan->id)) & ~STM32_MDMA_CCR_EN; ctcr = stm32_mdma_read(dmadev, STM32_MDMA_CTCR(chan->id)); ctbr = stm32_mdma_read(dmadev, STM32_MDMA_CTBR(chan->id)); @@ -965,7 +965,7 @@ stm32_mdma_prep_dma_memcpy(struct dma_chan *c, dma_addr_t dest, dma_addr_t src, if (!desc) return NULL; - ccr = stm32_mdma_read(dmadev, STM32_MDMA_CCR(chan->id)); + ccr = stm32_mdma_read(dmadev, STM32_MDMA_CCR(chan->id)) & ~STM32_MDMA_CCR_EN; ctcr = stm32_mdma_read(dmadev, STM32_MDMA_CTCR(chan->id)); ctbr = stm32_mdma_read(dmadev, STM32_MDMA_CTBR(chan->id)); cbndtr = stm32_mdma_read(dmadev, STM32_MDMA_CBNDTR(chan->id)); -- 2.7.4