Re: [PATCH v27] dmaengine: qcom: bam_dma: free interrupt before the clock in error path

[Bartosz Golaszewski]

On Thu, 8 Oct 2026 11:30:56 +0200, Bartosz Golaszewski
<bartosz.golaszewski@xxxxxxxxxxxxxxxx> said:
> The BAM interrupt is requested with a devres helper and so on error it's
> freed after probe() returns. We disable the clock before freeing or
> masking it so it may still fire and we may end up reading BAM registers
> with clock disabled.
>
> Stop using devres for interrupts as we free it in remove() manually
> anyway. Add an appropriate label and free the interrupt before disabling
> the clock in error path and in remove().
>
> Cc: stable@xxxxxxxxxxxxxxx
> Fixes: e7c0fe2a5c84 ("dmaengine: add Qualcomm BAM dma driver")
> Reported-by: Sashiko <sashiko-bot@xxxxxxxxxx>
> Closes: https://sashiko.dev/#/patchset/20260427-qcom-qce-cmd-descr-v16-0-945fd1cafbbc%40oss.qualcomm.com?part=2
> Reviewed-by: Manivannan Sadhasivam <mani@xxxxxxxxxx>
> Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@xxxxxxxxxxxxxxxx>
> ---
> This used to be part of the larger BAM DMA pipe locking series and never
> got picked up despite months on the list. I'm resending it separately.
> ---
> Changes in v27:
> - Rabase on top of current dma/next
> - Link to v26: https://patch.msgid.link/20261006-bam-dma-free-irq-v26-1-eef5c713d831@xxxxxxxxxxxxxxxx
>
> Changes in v26:
> - Rebased on top of current linux-next to address conflicts
> - Link to v25: https://patch.msgid.link/20261002-bam-dma-free-irq-v25-1-f39e01d19910@xxxxxxxxxxxxxxxx
>
> Changes in v25:
> - Don't touch remove(), it's not wrong in its current version
> - Link to v24: https://patch.msgid.link/20260723-qcom-qce-cmd-descr-v24-0-4f87bb4d9938@xxxxxxxxxxxxxxxx
> ---
>  drivers/dma/qcom/bam_dma.c | 10 ++++++----
>  1 file changed, 6 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/dma/qcom/bam_dma.c b/drivers/dma/qcom/bam_dma.c
> index 94cb957d4b187704e207361d629fde00e3e090bf..a626746b5c93496e5c5e885b35a856d38c284448 100644
> --- a/drivers/dma/qcom/bam_dma.c
> +++ b/drivers/dma/qcom/bam_dma.c
> @@ -1332,8 +1332,8 @@ static int bam_dma_probe(struct platform_device *pdev)
>  	for (i = 0; i < bdev->num_channels; i++)
>  		bam_channel_init(bdev, &bdev->channels[i], i);
>
> -	ret = devm_request_irq(bdev->dev, bdev->irq, bam_dma_irq,
> -			IRQF_TRIGGER_NONE, "bam_dma", bdev);
> +	ret = request_irq(bdev->irq, bam_dma_irq, IRQF_TRIGGER_HIGH,
> +			  "bam_dma", bdev);

Please disregard it version, this should have remained IRQF_TRIGGER_NONE.

Bart