[PATCH] dmaengine: fsl-edma: Fix clk leak on alloc_chan_resources failure

[PATCH] dmaengine: fsl-edma: Fix clk leak on alloc_chan_resources failure

[Zhen Ni]

When fsl_edma_alloc_chan_resources() fails after clk_prepare_enable(),
the error paths only free IRQs and destroy the TCD pool, but forget to
call clk_disable_unprepare(). This causes the channel clock to remain
enabled, leaking power and resources.

Fix it by disabling the channel clock in the error unwind path.

Fixes: d8d4355861d8 ("dmaengine: fsl-edma: add i.MX8ULP edma support")
Cc: stable@vger.kernel.org
Signed-off-by: Zhen Ni <zhen.ni@easystack.cn>
---
 drivers/dma/fsl-edma-common.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/dma/fsl-edma-common.c b/drivers/dma/fsl-edma-common.c
index 4976d7dde080..bd673f08f610 100644
--- a/drivers/dma/fsl-edma-common.c
+++ b/drivers/dma/fsl-edma-common.c
@@ -852,6 +852,8 @@ int fsl_edma_alloc_chan_resources(struct dma_chan *chan)
 		free_irq(fsl_chan->txirq, fsl_chan);
 err_txirq:
 	dma_pool_destroy(fsl_chan->tcd_pool);
+	if (fsl_edma_drvflags(fsl_chan) & FSL_EDMA_DRV_HAS_CHCLK)
+		clk_disable_unprepare(fsl_chan->clk);
 
 	return ret;
 }
-- 
2.20.1

Re: [PATCH] dmaengine: fsl-edma: Fix clk leak on alloc_chan_resources failure

[Frank Li]

On Fri, Oct 10, 2025 at 05:02:57PM +0800, Zhen Ni wrote:
> When fsl_edma_alloc_chan_resources() fails after clk_prepare_enable(),
> the error paths only free IRQs and destroy the TCD pool, but forget to
> call clk_disable_unprepare(). This causes the channel clock to remain
> enabled, leaking power and resources.
>
> Fix it by disabling the channel clock in the error unwind path.
>
> Fixes: d8d4355861d8 ("dmaengine: fsl-edma: add i.MX8ULP edma support")
> Cc: stable@vger.kernel.org
> Signed-off-by: Zhen Ni <zhen.ni@easystack.cn>
> ---
>  drivers/dma/fsl-edma-common.c | 2 ++
>  1 file changed, 2 insertions(+)
>
> diff --git a/drivers/dma/fsl-edma-common.c b/drivers/dma/fsl-edma-common.c
> index 4976d7dde080..bd673f08f610 100644
> --- a/drivers/dma/fsl-edma-common.c
> +++ b/drivers/dma/fsl-edma-common.c
> @@ -852,6 +852,8 @@ int fsl_edma_alloc_chan_resources(struct dma_chan *chan)
>  		free_irq(fsl_chan->txirq, fsl_chan);
>  err_txirq:
>  	dma_pool_destroy(fsl_chan->tcd_pool);
> +	if (fsl_edma_drvflags(fsl_chan) & FSL_EDMA_DRV_HAS_CHCLK)
> +		clk_disable_unprepare(fsl_chan->clk);

Thank you for your fix. clk API do nothing when input is NULL.

So check if (fsl_edma_drvflags(fsl_chan) & FSL_EDMA_DRV_HAS_CHCLK) is
reduntante.

I saw existed code have such check. You can clean up it.

Only need keep check at probe()
 fsl_chan->clk = devm_clk_get_enabled()

Frank
>
>  	return ret;
>  }
> --
> 2.20.1
>

[PATCH v2] dmaengine: fsl-edma: Fix clk leak on alloc_chan_resources failure

[Zhen Ni]

When fsl_edma_alloc_chan_resources() fails after clk_prepare_enable(),
the error paths only free IRQs and destroy the TCD pool, but forget to
call clk_disable_unprepare(). This causes the channel clock to remain
enabled, leaking power and resources. Since clk_disable_unprepare() is
safe to call with a NULL clk, the FSL_EDMA_DRV_HAS_CHCLK check is
reduntante.

Fix it by disabling the channel clock in the error unwind path.
Also clean up similar redundant checks in the driver for consistency.

Fixes: d8d4355861d8 ("dmaengine: fsl-edma: add i.MX8ULP edma support")
Cc: stable@vger.kernel.org
Suggested-by: Frank Li <Frank.Li@nxp.com>
Signed-off-by: Zhen Ni <zhen.ni@easystack.cn>
---
Changes in v2:
- Remove FSL_EDMA_DRV_HAS_CHCLK check
---
 drivers/dma/fsl-edma-common.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/dma/fsl-edma-common.c b/drivers/dma/fsl-edma-common.c
index 4976d7dde080..3007d5b7db55 100644
--- a/drivers/dma/fsl-edma-common.c
+++ b/drivers/dma/fsl-edma-common.c
@@ -852,6 +852,7 @@ int fsl_edma_alloc_chan_resources(struct dma_chan *chan)
 		free_irq(fsl_chan->txirq, fsl_chan);
 err_txirq:
 	dma_pool_destroy(fsl_chan->tcd_pool);
+	clk_disable_unprepare(fsl_chan->clk);
 
 	return ret;
 }
@@ -883,8 +884,7 @@ void fsl_edma_free_chan_resources(struct dma_chan *chan)
 	fsl_chan->is_sw = false;
 	fsl_chan->srcid = 0;
 	fsl_chan->is_remote = false;
-	if (fsl_edma_drvflags(fsl_chan) & FSL_EDMA_DRV_HAS_CHCLK)
-		clk_disable_unprepare(fsl_chan->clk);
+	clk_disable_unprepare(fsl_chan->clk);
 }
 
 void fsl_edma_cleanup_vchan(struct dma_device *dmadev)
-- 
2.20.1

Re: [PATCH v2] dmaengine: fsl-edma: Fix clk leak on alloc_chan_resources failure

[Frank Li]

On Sat, Oct 11, 2025 at 11:06:20AM +0800, Zhen Ni wrote:
> When fsl_edma_alloc_chan_resources() fails after clk_prepare_enable(),
> the error paths only free IRQs and destroy the TCD pool, but forget to
> call clk_disable_unprepare(). This causes the channel clock to remain
> enabled, leaking power and resources. Since clk_disable_unprepare() is
> safe to call with a NULL clk, the FSL_EDMA_DRV_HAS_CHCLK check is
> reduntante.
>
> Fix it by disabling the channel clock in the error unwind path.
> Also clean up similar redundant checks in the driver for consistency.
>
> Fixes: d8d4355861d8 ("dmaengine: fsl-edma: add i.MX8ULP edma support")
> Cc: stable@vger.kernel.org
> Suggested-by: Frank Li <Frank.Li@nxp.com>
> Signed-off-by: Zhen Ni <zhen.ni@easystack.cn>
> ---
> Changes in v2:
> - Remove FSL_EDMA_DRV_HAS_CHCLK check
> ---
>  drivers/dma/fsl-edma-common.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/dma/fsl-edma-common.c b/drivers/dma/fsl-edma-common.c
> index 4976d7dde080..3007d5b7db55 100644
> --- a/drivers/dma/fsl-edma-common.c
> +++ b/drivers/dma/fsl-edma-common.c
> @@ -852,6 +852,7 @@ int fsl_edma_alloc_chan_resources(struct dma_chan *chan)
>  		free_irq(fsl_chan->txirq, fsl_chan);
>  err_txirq:
>  	dma_pool_destroy(fsl_chan->tcd_pool);
> +	clk_disable_unprepare(fsl_chan->clk);
>
>  	return ret;
>  }
> @@ -883,8 +884,7 @@ void fsl_edma_free_chan_resources(struct dma_chan *chan)
>  	fsl_chan->is_sw = false;
>  	fsl_chan->srcid = 0;
>  	fsl_chan->is_remote = false;
> -	if (fsl_edma_drvflags(fsl_chan) & FSL_EDMA_DRV_HAS_CHCLK)
> -		clk_disable_unprepare(fsl_chan->clk);
> +	clk_disable_unprepare(fsl_chan->clk);

I may not say clearly at v1. this is cleanup patch, need seperated patch

You need two patches

first ones with fixes tags, to fix fsl_edma_alloc_chan_resources()'s problem

the second patches to do cleanup, remove redundant check
if (fsl_edma_drvflags(fsl_chan) & FSL_EDMA_DRV_HAS_CHCLK)

Frank


>  }
>
>  void fsl_edma_cleanup_vchan(struct dma_device *dmadev)
> --
> 2.20.1
>

[PATCH v3] dmaengine: fsl-edma: Fix clk leak on alloc_chan_resources failure

[Zhen Ni]

When fsl_edma_alloc_chan_resources() fails after clk_prepare_enable(),
the error paths only free IRQs and destroy the TCD pool, but forget to
call clk_disable_unprepare(). This causes the channel clock to remain
enabled, leaking power and resources.

Fix it by disabling the channel clock in the error unwind path.

Fixes: d8d4355861d8 ("dmaengine: fsl-edma: add i.MX8ULP edma support")
Cc: stable@vger.kernel.org
Suggested-by: Frank Li <Frank.Li@nxp.com>
Signed-off-by: Zhen Ni <zhen.ni@easystack.cn>
---
Changes in v2:
- Remove FSL_EDMA_DRV_HAS_CHCLK check
Changes in v3:
- Remove cleanup
---
 drivers/dma/fsl-edma-common.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/dma/fsl-edma-common.c b/drivers/dma/fsl-edma-common.c
index 4976d7dde080..11655dcc4d6c 100644
--- a/drivers/dma/fsl-edma-common.c
+++ b/drivers/dma/fsl-edma-common.c
@@ -852,6 +852,7 @@ int fsl_edma_alloc_chan_resources(struct dma_chan *chan)
 		free_irq(fsl_chan->txirq, fsl_chan);
 err_txirq:
 	dma_pool_destroy(fsl_chan->tcd_pool);
+	clk_disable_unprepare(fsl_chan->clk);
 
 	return ret;
 }
-- 
2.20.1