Re: [PATCH] dmaengine: altera-msgdma: initialize state before requesting IRQ

[Frank Li]

On Sun, Aug 30, 2026 at 01:33:08PM +0800, Runyu Xiao wrote:
> msgdma_probe() registers the IRQ before initializing the tasklet, lock,
> and descriptor lists used by the interrupt handler. A pending interrupt
> can access incomplete state during probe.
>
> Initialize the handler state before requesting the IRQ so the interrupt
> path observes ready software state.
>
> Fixes: a85c6f1b2921 ("dmaengine: Add driver for Altera / Intel mSGDMA IP core")
> Cc: stable@xxxxxxxxxxxxxxx
> Assisted-by: Codex:GPT-5
> Signed-off-by: Runyu Xiao <runyu.xiao@xxxxxxxxxx>
> ---

Reviewed-by: Frank Li <Frank.Li@xxxxxxx>

>  drivers/dma/altera-msgdma.c | 10 +++++-----
>  1 file changed, 5 insertions(+), 5 deletions(-)
>
> diff --git a/drivers/dma/altera-msgdma.c b/drivers/dma/altera-msgdma.c
> index e23e5b441..412f4bce1 100644
> --- a/drivers/dma/altera-msgdma.c
> +++ b/drivers/dma/altera-msgdma.c
> @@ -847,11 +847,6 @@ static int msgdma_probe(struct platform_device *pdev)
>  	if (mdev->irq < 0)
>  		return -ENXIO;
>
> -	ret = devm_request_irq(&pdev->dev, mdev->irq, msgdma_irq_handler,
> -			       0, dev_name(&pdev->dev), mdev);
> -	if (ret)
> -		return ret;
> -
>  	tasklet_setup(&mdev->irq_tasklet, msgdma_tasklet);
>
>  	dma_cookie_init(&mdev->dmachan);
> @@ -863,6 +858,11 @@ static int msgdma_probe(struct platform_device *pdev)
>  	INIT_LIST_HEAD(&mdev->done_list);
>  	INIT_LIST_HEAD(&mdev->free_list);
>
> +	ret = devm_request_irq(&pdev->dev, mdev->irq, msgdma_irq_handler,
> +			       0, dev_name(&pdev->dev), mdev);
> +	if (ret)
> +		return ret;
> +
>  	dma_dev = &mdev->dmadev;
>
>  	/* Set DMA capabilities */
> --
> 2.34.1