Hi Vitalii,
Le lundi 20 janvier 2025 à 16:50 +0300, Vitalii Mordan a écrit :
> If the clock jzdma->clk was not enabled in jz4780_dma_probe(), it
> should
> not be disabled in any path.
>
> Conversely, if it was enabled in jz4780_dma_probe(), it must be
> disabled
> in all error paths to ensure proper cleanup.
>
> Use the devm_clk_get_enabled() helper function to ensure proper call
> balance for jzdma->clk.
>
> Found by Linux Verification Center (linuxtesting.org) with Klever.
>
> Fixes: d894fc6046fe ("dmaengine: jz4780: add driver for the Ingenic
> JZ4780 DMA controller")
> Signed-off-by: Vitalii Mordan <mordan@xxxxxxxxx>
Acked-by: Paul Cercueil <paul@xxxxxxxxxxxxxxx>
Cheers,
-Paul
> ---
> drivers/dma/dma-jz4780.c | 14 ++++----------
> 1 file changed, 4 insertions(+), 10 deletions(-)
>
> diff --git a/drivers/dma/dma-jz4780.c b/drivers/dma/dma-jz4780.c
> index 100057603fd4..ff9c387fd8c1 100644
> --- a/drivers/dma/dma-jz4780.c
> +++ b/drivers/dma/dma-jz4780.c
> @@ -896,15 +896,13 @@ static int jz4780_dma_probe(struct
> platform_device *pdev)
> return -EINVAL;
> }
>
> - jzdma->clk = devm_clk_get(dev, NULL);
> + jzdma->clk = devm_clk_get_enabled(dev, NULL);
> if (IS_ERR(jzdma->clk)) {
> - dev_err(dev, "failed to get clock\n");
> + dev_err(dev, "failed to get and enable clock\n");
> ret = PTR_ERR(jzdma->clk);
> return ret;
> }
>
> - clk_prepare_enable(jzdma->clk);
> -
> /* Property is optional, if it doesn't exist the value will
> remain 0. */
> of_property_read_u32_index(dev->of_node, "ingenic,reserved-
> channels",
> 0, &jzdma->chan_reserved);
> @@ -972,7 +970,7 @@ static int jz4780_dma_probe(struct
> platform_device *pdev)
>
> ret = platform_get_irq(pdev, 0);
> if (ret < 0)
> - goto err_disable_clk;
> + return ret;
>
> jzdma->irq = ret;
>
> @@ -980,7 +978,7 @@ static int jz4780_dma_probe(struct
> platform_device *pdev)
> jzdma);
> if (ret) {
> dev_err(dev, "failed to request IRQ %u!\n", jzdma-
> >irq);
> - goto err_disable_clk;
> + return ret;
> }
>
> ret = dmaenginem_async_device_register(dd);
> @@ -1002,9 +1000,6 @@ static int jz4780_dma_probe(struct
> platform_device *pdev)
>
> err_free_irq:
> free_irq(jzdma->irq, jzdma);
> -
> -err_disable_clk:
> - clk_disable_unprepare(jzdma->clk);
> return ret;
> }
>
> @@ -1015,7 +1010,6 @@ static void jz4780_dma_remove(struct
> platform_device *pdev)
>
> of_dma_controller_free(pdev->dev.of_node);
>
> - clk_disable_unprepare(jzdma->clk);
> free_irq(jzdma->irq, jzdma);
>
> for (i = 0; i < jzdma->soc_data->nb_channels; i++)
