Hi Amélie,
thanks a lot.
Tested-by: Alain Volmat <alain.volmat@xxxxxxxxxxx>
Regards,
Alain
On Mon, Oct 09, 2023 at 10:24:50AM +0200, Amelie Delaunay wrote:
> From: Alain Volmat <alain.volmat@xxxxxxxxxxx>
>
> 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@xxxxxxxxxxx>
> Signed-off-by: Amelie Delaunay <amelie.delaunay@xxxxxxxxxxx>
> Cc: stable@xxxxxxxxxxxxxxx
> ---
> 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
>
