Re: [PATCH v3] mailbox: mtk-cmdq: Do not request irq until we are ready

[Chun-Kuang Hu]

Ricardo Ribalda <ribalda@xxxxxxxxxxxx> 於 2022年11月30日 週三 晚上8:59寫道：
>
> If the system comes from kexec() the peripheral might trigger an IRQ
> befoe we are ready for it. Triggering a crash due to an access to
> invalid memory.

Reviewed-by: Chun-Kuang Hu <chunkuang.hu@xxxxxxxxxx>

>
> Signed-off-by: Ricardo Ribalda <ribalda@xxxxxxxxxxxx>
> ---
> To: AngeloGioacchino Del Regno <angelogioacchino.delregno@xxxxxxxxxxxxx>
> To: Jassi Brar <jassisinghbrar@xxxxxxxxx>
> To: Matthias Brugger <matthias.bgg@xxxxxxxxx>
> Cc: linux-kernel@xxxxxxxxxxxxxxx
> Cc: linux-arm-kernel@xxxxxxxxxxxxxxxxxxx
> Cc: linux-mediatek@xxxxxxxxxxxxxxxxxxx
> ---
> Changes in v3:
> - Rebase on top of https://patchwork.kernel.org/project/linux-mediatek/patch/20221102100736.37815-1-angelogioacchino.delregno@xxxxxxxxxxxxx/
> - Link to v2: https://lore.kernel.org/r/20221125-mtk-mailbox-v2-0-886f70c7173c@xxxxxxxxxxxx
>
> Changes in v2:
> - I have managed to repro a different panic. Moving the irq enabling to the very end of probe.
> - Link to v1: https://lore.kernel.org/r/20221125-mtk-mailbox-v1-0-2e3ee120850c@xxxxxxxxxxxx
> ---
>  drivers/mailbox/mtk-cmdq-mailbox.c | 13 +++++++------
>  1 file changed, 7 insertions(+), 6 deletions(-)
>
> diff --git a/drivers/mailbox/mtk-cmdq-mailbox.c b/drivers/mailbox/mtk-cmdq-mailbox.c
> index a460ee26eb11..b18d47ea13a0 100644
> --- a/drivers/mailbox/mtk-cmdq-mailbox.c
> +++ b/drivers/mailbox/mtk-cmdq-mailbox.c
> @@ -569,12 +569,6 @@ static int cmdq_probe(struct platform_device *pdev)
>         }
>
>         cmdq->irq_mask = GENMASK(cmdq->pdata->thread_nr - 1, 0);
> -       err = devm_request_irq(dev, cmdq->irq, cmdq_irq_handler, IRQF_SHARED,
> -                              "mtk_cmdq", cmdq);
> -       if (err < 0) {
> -               dev_err(dev, "failed to register ISR (%d)\n", err);
> -               return err;
> -       }
>
>         dev_dbg(dev, "cmdq device: addr:0x%p, va:0x%p, irq:%d\n",
>                 dev, cmdq->base, cmdq->irq);
> @@ -641,6 +635,13 @@ static int cmdq_probe(struct platform_device *pdev)
>
>         cmdq_init(cmdq);
>
> +       err = devm_request_irq(dev, cmdq->irq, cmdq_irq_handler, IRQF_SHARED,
> +                              "mtk_cmdq", cmdq);
> +       if (err < 0) {
> +               dev_err(dev, "failed to register ISR (%d)\n", err);
> +               return err;
> +       }
> +
>         return 0;
>  }
>
>
> ---
> base-commit: 1642107db81361b4339643eb90af4839e2cf229f
> change-id: 20221125-mtk-mailbox-ba6cbd1d91b6
>
> Best regards,
> --
> Ricardo Ribalda <ribalda@xxxxxxxxxxxx>
>