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

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

[Ricardo Ribalda]

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.

Signed-off-by: Ricardo Ribalda <ribalda@chromium.org>
---
To: Jassi Brar <jassisinghbrar@gmail.com>
To: Matthias Brugger <matthias.bgg@gmail.com>
Cc: linux-kernel@vger.kernel.org
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-mediatek@lists.infradead.org
---
 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 9465f9081515..829f1ef3309f 100644
--- a/drivers/mailbox/mtk-cmdq-mailbox.c
+++ b/drivers/mailbox/mtk-cmdq-mailbox.c
@@ -545,12 +545,6 @@ static int cmdq_probe(struct platform_device *pdev)
 	cmdq->control_by_sw = plat_data->control_by_sw;
 	cmdq->gce_num = plat_data->gce_num;
 	cmdq->irq_mask = GENMASK(cmdq->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);
@@ -613,6 +607,13 @@ static int cmdq_probe(struct platform_device *pdev)
 
 	platform_set_drvdata(pdev, 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;
+	}
+
 	WARN_ON(clk_bulk_prepare(cmdq->gce_num, cmdq->clocks));
 
 	cmdq_init(cmdq);

---
base-commit: 4312098baf37ee17a8350725e6e0d0e8590252d4
change-id: 20221125-mtk-mailbox-ba6cbd1d91b6

Best regards,
-- 
Ricardo Ribalda <ribalda@chromium.org>

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

[AngeloGioacchino Del Regno]

Il 25/11/22 17:19, Ricardo Ribalda ha scritto:
> 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.
> 
> Signed-off-by: Ricardo Ribalda <ribalda@chromium.org>

I agree on this change, but I've already sent a patch that's been reviewed
by multiple people (hence ready to be picked), on top of which this patch
will not apply.

Can you please rebase this patch on top of [1]?

Thanks,
Angelo

[1]: 
https://patchwork.kernel.org/project/linux-mediatek/patch/20221102100736.37815-1-angelogioacchino.delregno@collabora.com/

> ---
> To: Jassi Brar <jassisinghbrar@gmail.com>
> To: Matthias Brugger <matthias.bgg@gmail.com>
> Cc: linux-kernel@vger.kernel.org
> Cc: linux-arm-kernel@lists.infradead.org
> Cc: linux-mediatek@lists.infradead.org
> ---
>   drivers/mailbox/mtk-cmdq-mailbox.c | 13 +++++++------
>   1 file changed, 7 insertions(+), 6 deletions(-)
> 
> 
> ---
> base-commit: 4312098baf37ee17a8350725e6e0d0e8590252d4
> change-id: 20221125-mtk-mailbox-ba6cbd1d91b6
> 
> Best regards,
> 
> diff --git a/drivers/mailbox/mtk-cmdq-mailbox.c b/drivers/mailbox/mtk-cmdq-mailbox.c
> index 9465f9081515..829f1ef3309f 100644
> --- a/drivers/mailbox/mtk-cmdq-mailbox.c
> +++ b/drivers/mailbox/mtk-cmdq-mailbox.c
> @@ -545,12 +545,6 @@ static int cmdq_probe(struct platform_device *pdev)
>   	cmdq->control_by_sw = plat_data->control_by_sw;
>   	cmdq->gce_num = plat_data->gce_num;
>   	cmdq->irq_mask = GENMASK(cmdq->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);
> @@ -613,6 +607,13 @@ static int cmdq_probe(struct platform_device *pdev)
>   
>   	platform_set_drvdata(pdev, 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;
> +	}
> +
>   	WARN_ON(clk_bulk_prepare(cmdq->gce_num, cmdq->clocks));
>   
>   	cmdq_init(cmdq);
>