linux-kernel - Re: [PATCH 1/3] aspeed-video: add error message for unhandled interrupts

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Date:   Tue, 22 Dec 2020 04:34:26 +0000
From:   Joel Stanley <joel@....id.au>
To:     Zev Weiss <zev@...ilderbeest.net>,
        Jae Hyun Yoo <jae.hyun.yoo@...ux.intel.com>,
        Ryan Chen <ryan_chen@...eedtech.com>
Cc:     Eddie James <eajames@...ux.ibm.com>,
        Mauro Carvalho Chehab <mchehab@...nel.org>,
        Andrew Jeffery <andrew@...id.au>, linux-media@...r.kernel.org,
        OpenBMC Maillist <openbmc@...ts.ozlabs.org>,
        Linux ARM <linux-arm-kernel@...ts.infradead.org>,
        linux-aspeed <linux-aspeed@...ts.ozlabs.org>,
        Linux Kernel Mailing List <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH 1/3] aspeed-video: add error message for unhandled interrupts

On Tue, 15 Dec 2020 at 02:46, Zev Weiss <zev@...ilderbeest.net> wrote:
>
> This device seems to have a propensity for asserting interrupts that
> aren't enabled -- in addition to the CAPTURE_COMPLETE and FRAME_COMPLETE
> interrupts squashed in commit 65d270acb2d662c3346793663ac3a759eb4491b8,
> COMP_READY has also been observed.  Adding a message diagnosing what
> happened in the event of unhandled interrupt status bits should
> hopefully make the debugging process simpler for any others that pop up
> in the future.

Ryan, is this a known issue with the video engine hardware?

>
> Signed-off-by: Zev Weiss <zev@...ilderbeest.net>
> ---
>  drivers/media/platform/aspeed-video.c | 5 +++++
>  1 file changed, 5 insertions(+)
>
> diff --git a/drivers/media/platform/aspeed-video.c b/drivers/media/platform/aspeed-video.c
> index 7d98db1d9b52..eb02043532e3 100644
> --- a/drivers/media/platform/aspeed-video.c
> +++ b/drivers/media/platform/aspeed-video.c
> @@ -562,6 +562,7 @@ static irqreturn_t aspeed_video_irq(int irq, void *arg)
>  {
>         struct aspeed_video *video = arg;
>         u32 sts = aspeed_video_read(video, VE_INTERRUPT_STATUS);
> +       u32 orig_sts = sts;
>
>         /*
>          * Resolution changed or signal was lost; reset the engine and
> @@ -639,6 +640,10 @@ static irqreturn_t aspeed_video_irq(int irq, void *arg)
>         if (sts & VE_INTERRUPT_FRAME_COMPLETE)
>                 sts &= ~VE_INTERRUPT_FRAME_COMPLETE;
>
> +       if (sts)
> +               dev_err_ratelimited(video->dev, "unexpected interrupt asserted:"
> +                                   " sts=%08x, orig_sts=%08x", sts, orig_sts);

Do you want to do this before clearing the FRAME and CAPTURE bits?

> +
>         return sts ? IRQ_NONE : IRQ_HANDLED;
>  }
>
> --
> 2.29.2
>