[PATCH 5.13 030/175] dmaengine: stm32-dmamux: Fix PM usage counter unbalance in stm32 dmamux ops

From: Greg Kroah-Hartman
Date: Tue Aug 10 2021 - 13:57:07 EST


From: Zhang Qilong <zhangqilong3@xxxxxxxxxx>

[ Upstream commit baa16371c9525f24d508508e4d296c031e1de29c ]

pm_runtime_get_sync will increment pm usage counter
even it failed. Forgetting to putting operation will
result in reference leak here. We fix it by replacing
it with pm_runtime_resume_and_get to keep usage counter
balanced.

Fixes: 4f3ceca254e0f ("dmaengine: stm32-dmamux: Add PM Runtime support")
Signed-off-by: Zhang Qilong <zhangqilong3@xxxxxxxxxx>
Link: https://lore.kernel.org/r/20210607064640.121394-3-zhangqilong3@xxxxxxxxxx
Signed-off-by: Vinod Koul <vkoul@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
drivers/dma/stm32-dmamux.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/dma/stm32-dmamux.c b/drivers/dma/stm32-dmamux.c
index ef0d0555103d..a42164389ebc 100644
--- a/drivers/dma/stm32-dmamux.c
+++ b/drivers/dma/stm32-dmamux.c
@@ -137,7 +137,7 @@ static void *stm32_dmamux_route_allocate(struct of_phandle_args *dma_spec,

/* Set dma request */
spin_lock_irqsave(&dmamux->lock, flags);
- ret = pm_runtime_get_sync(&pdev->dev);
+ ret = pm_runtime_resume_and_get(&pdev->dev);
if (ret < 0) {
spin_unlock_irqrestore(&dmamux->lock, flags);
goto error;
@@ -336,7 +336,7 @@ static int stm32_dmamux_suspend(struct device *dev)
struct stm32_dmamux_data *stm32_dmamux = platform_get_drvdata(pdev);
int i, ret;

- ret = pm_runtime_get_sync(dev);
+ ret = pm_runtime_resume_and_get(dev);
if (ret < 0)
return ret;

@@ -361,7 +361,7 @@ static int stm32_dmamux_resume(struct device *dev)
if (ret < 0)
return ret;

- ret = pm_runtime_get_sync(dev);
+ ret = pm_runtime_resume_and_get(dev);
if (ret < 0)
return ret;

--
2.30.2