Re: [PATCH] drm/msm: Disable frequency clamping on a630

From: Amit Pundir <amit.pundir@linaro.org>
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>
Subject: Re: [PATCH] drm/msm: Disable frequency clamping on a630
Date: Tue, 7 Sep 2021 13:55:22 +0530	[thread overview]
Message-ID: <CAMi1Hd20xd0Lrp0MuKo=HdDPKeNC_DW08iFoF5wseCH5eB=FzQ@mail.gmail.com> (raw)
In-Reply-To: <CAF6AEGugB5QinhyOxvAiG_V40=mXS20nnqxgk71xe_fmm1iZsw@mail.gmail.com>

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