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References: <20230628-topic-a7xx_drmmsm-v2-0-1439e1b2343f@linaro.org> <20230628-topic-a7xx_drmmsm-v2-13-1439e1b2343f@linaro.org>
In-Reply-To: <20230628-topic-a7xx_drmmsm-v2-13-1439e1b2343f@linaro.org>
From:   Rob Clark <robdclark@gmail.com>
Date:   Wed, 9 Aug 2023 15:15:17 -0700
Message-ID: <CAF6AEGsJ1WyLttZcvkgJjxsHHxX-uyz6+yb4=xizqakeZrSdTQ@mail.gmail.com>
Subject: Re: [PATCH v2 13/14] drm/msm/a6xx: Vastly increase HFI timeout
To:     Konrad Dybcio <konrad.dybcio@linaro.org>
Cc:     Abhinav Kumar <quic_abhinavk@quicinc.com>,
        Dmitry Baryshkov <dmitry.baryshkov@linaro.org>,
        Sean Paul <sean@poorly.run>, David Airlie <airlied@gmail.com>,
        Daniel Vetter <daniel@ffwll.ch>,
        Rob Herring <robh+dt@kernel.org>,
        Krzysztof Kozlowski <krzysztof.kozlowski+dt@linaro.org>,
        Conor Dooley <conor+dt@kernel.org>,
        Bjorn Andersson <andersson@kernel.org>,
        Marijn Suijten <marijn.suijten@somainline.org>,
        linux-arm-msm@vger.kernel.org, dri-devel@lists.freedesktop.org,
        freedreno@lists.freedesktop.org, devicetree@vger.kernel.org,
        linux-kernel@vger.kernel.org,
        Neil Armstrong <neil.armstrong@linaro.org>
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On Tue, Aug 8, 2023 at 2:03=E2=80=AFPM Konrad Dybcio <konrad.dybcio@linaro.=
org> wrote:
>
> A7xx GMUs can be slow as molasses at times.
> Increase the timeout to 1 second to match the vendor driver.
>
> Tested-by: Neil Armstrong <neil.armstrong@linaro.org> # on SM8550-QRD
> Tested-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org> # sm8450
> Signed-off-by: Konrad Dybcio <konrad.dybcio@linaro.org>
> ---
>  drivers/gpu/drm/msm/adreno/a6xx_hfi.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/gpu/drm/msm/adreno/a6xx_hfi.c b/drivers/gpu/drm/msm/=
adreno/a6xx_hfi.c
> index cdb3f6e74d3e..e25ddb82a087 100644
> --- a/drivers/gpu/drm/msm/adreno/a6xx_hfi.c
> +++ b/drivers/gpu/drm/msm/adreno/a6xx_hfi.c
> @@ -108,7 +108,7 @@ static int a6xx_hfi_wait_for_ack(struct a6xx_gmu *gmu=
, u32 id, u32 seqnum,
>
>         /* Wait for a response */
>         ret =3D gmu_poll_timeout(gmu, REG_A6XX_GMU_GMU2HOST_INTR_INFO, va=
l,
> -               val & A6XX_GMU_GMU2HOST_INTR_INFO_MSGQ, 100, 5000);
> +               val & A6XX_GMU_GMU2HOST_INTR_INFO_MSGQ, 100, 1000000);

yikes.. so our default autosuspend delay is 66ms.. and we hit this
path in the resume path (ie. if you click something after things have
been sitting idle for >66ms).. you really don't want something in that
critical path to take 1sec

BR,
-R

>
>         if (ret) {
>                 DRM_DEV_ERROR(gmu->dev,
>
> --
> 2.41.0
>