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dmaengine: img-mdc: Fix runtime PM usage counter leak

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pm_runtime_get_sync() leaves the IMG MDC device's usage counter
incremented when runtime resume fails. mdc_alloc_chan_resources() returns
that error to the DMA core, so the channel's client count is not
incremented and mdc_free_chan_resources() is not called to drop the
reference. Repeated allocation attempts can therefore accumulate usage
references and prevent runtime suspend.

Use pm_runtime_resume_and_get() so a failed resume does not retain a
usage reference while successful allocations remain paired with
mdc_free_chan_resources(). DMA core only treats negative return values as
allocation failures, so the helper's zero success return preserves
behavior.

This issue was found by a static analysis checker and confirmed by manual
source review.

Fixes: 56d355e6f5 ("dmaengine: img-mdc: Add runtime PM")
Signed-off-by: Ruoyu Wang <ruoyuw560@gmail.com>
Reviewed-by: Frank Li <Frank.Li@nxp.com>
Link: https://patch.msgid.link/20260813153143.3953303-1-ruoyuw560@gmail.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
This commit is contained in:
Ruoyu Wang 2026-08-13 23:31:43 +08:00 committed by Vinod Koul
parent f10d96b1c5
commit 4a1a2d8b85
1 changed files with 1 additions and 1 deletions
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2
drivers/dma/img-mdc-dma.c
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@ -738,7 +738,7 @@ static int mdc_alloc_chan_resources(struct dma_chan *chan)
struct mdc_chan *mchan = to_mdc_chan(chan);
struct device *dev = mdma2dev(mchan->mdma);
return pm_runtime_get_sync(dev);
return pm_runtime_resume_and_get(dev);
}
static void mdc_free_chan_resources(struct dma_chan *chan)