4.19-stable review patch. If anyone has any objections, please let me know.
------------------
From: Alain Volmat alain.volmat@foss.st.com
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 alain.volmat@foss.st.com Signed-off-by: Amelie Delaunay amelie.delaunay@foss.st.com Cc: stable@vger.kernel.org Tested-by: Alain Volmat alain.volmat@foss.st.com Link: https://lore.kernel.org/r/20231009082450.452877-1-amelie.delaunay@foss.st.co... Signed-off-by: Vinod Koul vkoul@kernel.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/dma/stm32-mdma.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)
--- a/drivers/dma/stm32-mdma.c +++ b/drivers/dma/stm32-mdma.c @@ -520,7 +520,7 @@ static int stm32_mdma_set_xfer_param(str 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));
@@ -948,7 +948,7 @@ stm32_mdma_prep_dma_memcpy(struct dma_ch 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));