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From:   Amit Pundir <amit.pundir@linaro.org>
Date:   Tue, 7 Sep 2021 13:55:22 +0530
Message-ID: <CAMi1Hd20xd0Lrp0MuKo=HdDPKeNC_DW08iFoF5wseCH5eB=FzQ@mail.gmail.com>
Subject: Re: [PATCH] drm/msm: Disable frequency clamping on a630
To:     Rob Clark <robdclark@gmail.com>
Cc:     John Stultz <john.stultz@linaro.org>,
        Caleb Connolly <caleb.connolly@linaro.org>,
        Rob Clark <robdclark@chromium.org>,
        freedreno <freedreno@lists.freedesktop.org>,
        Sai Prakash Ranjan <saiprakash.ranjan@codeaurora.org>,
        Jonathan Marek <jonathan@marek.ca>,
        David Airlie <airlied@linux.ie>,
        linux-arm-msm <linux-arm-msm@vger.kernel.org>,
        Akhil P Oommen <akhilpo@codeaurora.org>,
        dri-devel <dri-devel@lists.freedesktop.org>,
        Jordan Crouse <jordan@cosmicpenguin.net>,
        Stephen Boyd <sboyd@kernel.org>,
        Bjorn Andersson <bjorn.andersson@linaro.org>,
        Sean Paul <sean@poorly.run>,
        open list <linux-kernel@vger.kernel.org>
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On Tue, 7 Sept 2021 at 07:11, Rob Clark <robdclark@gmail.com> wrote:
>
> One thing I thought of, which would be worth ruling out, is whether
> this issue only occurs with freq changes immediately after resuming
> the GPU, vs freq changes in general.  Could you try the below patch.
> And if it "fixes" the issue, then try reducing the delay until you
> start seeing GPU hangs again.

It doesn't fix the crash and I can still reproduce it
https://pastebin.com/raw/bxK4mAhB

>
> ----------
> diff --git a/drivers/gpu/drm/msm/adreno/a6xx_gpu.c
> b/drivers/gpu/drm/msm/adreno/a6xx_gpu.c
> index 40c9fef457a4..278b85207ea3 100644
> --- a/drivers/gpu/drm/msm/adreno/a6xx_gpu.c
> +++ b/drivers/gpu/drm/msm/adreno/a6xx_gpu.c
> @@ -1513,6 +1513,8 @@ static int a6xx_pm_resume(struct msm_gpu *gpu)
>   if (ret)
>   return ret;
>
> + msleep(5);
> +
>   msm_devfreq_resume(gpu);
>
>   a6xx_llc_activate(a6xx_gpu);
> ----------
>
> BR,
> -R