[PATCH] dma: jz4780: handle clk_prepare_enable() failure in probe

[PATCH] dma: jz4780: handle clk_prepare_enable() failure in probe

[Jiawen Liu]

From: jiawen <1298662399@qq.com>

jz4780_dma_probe() ignores the return value of clk_prepare_enable(). If
the clock fails to enable, the driver continues and may later attempt to
disable an unprepared clock on error paths, leading to unbalanced clock
operations.

Check the return value and propagate the error immediately, avoiding the
erroneous cleanup.

Signed-off-by: jiawen <1298662399@qq.com>
---
diff --git a/drivers/dma/dma-jz4780.c b/drivers/dma/dma-jz4780.c
--- a/drivers/dma/dma-jz4780.c
+++ b/drivers/dma/dma-jz4780.c
@@ -903,7 +903,9 @@
 		return ret;
 	}
 
-	clk_prepare_enable(jzdma->clk);
+	ret = clk_prepare_enable(jzdma->clk);
+	if (ret)
+		return ret;
 
 	/* Property is optional, if it doesn't exist the value will remain 0. */
 	of_property_read_u32_index(dev->of_node, "ingenic,reserved-channels",

Re: [PATCH] dma: jz4780: handle clk_prepare_enable() failure in probe

[Frank Li]

On Tue, Aug 18, 2026 at 04:41:31PM +0400, Jiawen Liu wrote:
> From: jiawen <1298662399@qq.com>

subject:

dmaengine: jz4780: propagate the return value of clk_prepare_enable() in probe

Frank
>
> jz4780_dma_probe() ignores the return value of clk_prepare_enable(). If
> the clock fails to enable, the driver continues and may later attempt to
> disable an unprepared clock on error paths, leading to unbalanced clock
> operations.
>
> Check the return value and propagate the error immediately, avoiding the
> erroneous cleanup.
>
> Signed-off-by: jiawen <1298662399@qq.com>
> ---
> diff --git a/drivers/dma/dma-jz4780.c b/drivers/dma/dma-jz4780.c
> --- a/drivers/dma/dma-jz4780.c
> +++ b/drivers/dma/dma-jz4780.c
> @@ -903,7 +903,9 @@
>  		return ret;
>  	}
>
> -	clk_prepare_enable(jzdma->clk);
> +	ret = clk_prepare_enable(jzdma->clk);
> +	if (ret)
> +		return ret;
>
>  	/* Property is optional, if it doesn't exist the value will remain 0. */
>  	of_property_read_u32_index(dev->of_node, "ingenic,reserved-channels",
>

Re: [PATCH] dma: jz4780: handle clk_prepare_enable() failure in probe

[Markus Elfring]

…
> Check the return value and propagate the error immediately, avoiding the
> erroneous cleanup.

How do you think about to add any tags (like “Fixes” and “Cc”) accordingly?
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/Documentation/process/submitting-patches.rst?h=v7.2#n145
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/Documentation/process/stable-kernel-rules.rst?h=v7.2#n34

Regards,
Markus