On 09-10-23, 11:02, Alain Volmat wrote:

Hi Amélie,

thanks a lot.

Tested-by: Alain Volmat alain.volmat@foss.st.com

Please **do ** not ** top post!

Regards, Alain

On Mon, Oct 09, 2023 at 10:24:50AM +0200, Amelie Delaunay wrote:

...

From: Alain Volmat alain.volmat@foss.st.com

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 alain.volmat@foss.st.com Signed-off-by: Amelie Delaunay amelie.delaunay@foss.st.com Cc: stable@vger.kernel.org

---

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 bae08b3f55c7..f414efdbd809 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));

-- 2.25.1