[PATCH 6.18 332/752] dmaengine: stm32-mdma: initialize m2m_hw_period and ccr to fix warnings

Sasha Levin
2026-02-28T17:52:46Z

From: Clément Le Goffic <clement.legoffic@foss.st.com>

[ Upstream commit aaf3bc0265744adbc2d364964ef409cf118d193d ]

m2m_hw_period is initialized only when chan_config->m2m_hw is true. This
triggers a warning:
‘m2m_hw_period’ may be used uninitialized [-Wmaybe-uninitialized]
Although m2m_hw_period is only used when chan_config->m2m_hw is true and
ignored otherwise, initialize it unconditionally to 0.

ccr is initialized by stm32_mdma_set_xfer_param() when the sg list is not
empty. This triggers a warning:
‘ccr’ may be used uninitialized [-Wmaybe-uninitialized]
Indeed, it could be used uninitialized if the sg list is empty. Initialize
it to 0.

Signed-off-by: Clément Le Goffic <clement.legoffic@foss.st.com>
Reviewed-by: Clément Le Goffic <legoffic.clement@gmail.com>
Signed-off-by: Amelie Delaunay <amelie.delaunay@foss.st.com>
Link: https://patch.msgid.link/20251217-mdma_warnings_fix-v2-1-340200e0bb55@foss.st.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/dma/stm32/stm32-mdma.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/dma/stm32/stm32-mdma.c b/drivers/dma/stm32/stm32-mdma.c
index 080c1c725216c..b87d41b234df1 100644
--- a/drivers/dma/stm32/stm32-mdma.c
+++ b/drivers/dma/stm32/stm32-mdma.c
@@ -731,7 +731,7 @@ static int stm32_mdma_setup_xfer(struct stm32_mdma_chan *chan,
struct stm32_mdma_chan_config *chan_config = &chan->chan_config;
struct scatterlist *sg;
dma_addr_t src_addr, dst_addr;
- u32 m2m_hw_period, ccr, ctcr, ctbr;
+ u32 m2m_hw_period = 0, ccr = 0, ctcr, ctbr;
int i, ret = 0;

if (chan_config->m2m_hw)
--
2.51.0