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authorAlain Volmat2023-10-09 10:24:50 +0200
committerGreg Kroah-Hartman2023-11-28 17:07:13 +0000
commit7fc465d2653a0b9ff5d804d2139ca99f2c33656f (patch)
treef69d0ee9147e39cdd782d6b695c31e3433a6bb81 /drivers/dma
parent55d699e2d2ef7ff5a4ca6751f25dd84b29d11b1c (diff)
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 <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.com Signed-off-by: Vinod Koul <vkoul@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/dma')
-rw-r--r--drivers/dma/stm32-mdma.c4
1 files changed, 2 insertions, 2 deletions
diff --git a/drivers/dma/stm32-mdma.c b/drivers/dma/stm32-mdma.c
index 4e9bab61f466..65ef1f5ca6b8 100644
--- a/drivers/dma/stm32-mdma.c
+++ b/drivers/dma/stm32-mdma.c
@@ -490,7 +490,7 @@ 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));
@@ -966,7 +966,7 @@ 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));