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Message-ID: <b1740f38-81f2-32d3-e900-30f6e2ad970b@quicinc.com>
Date:   Sat, 5 Mar 2022 00:52:25 +0530
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Subject: Re: [PATCH v1 07/10] drm/msm/adreno: Retry on gpu resume failure
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To:     AngeloGioacchino Del Regno 
        <angelogioacchino.delregno@collabora.com>,
        freedreno <freedreno@lists.freedesktop.org>,
        <dri-devel@lists.freedesktop.org>, <linux-arm-msm@vger.kernel.org>,
        Rob Clark <robdclark@gmail.com>,
        Dmitry Baryshkov <dmitry.baryshkov@linaro.org>,
        "Bjorn Andersson" <bjorn.andersson@linaro.org>
CC:     Abhinav Kumar <quic_abhinavk@quicinc.com>,
        Daniel Vetter <daniel@ffwll.ch>,
        David Airlie <airlied@linux.ie>,
        Jonathan Marek <jonathan@marek.ca>,
        Sean Paul <sean@poorly.run>,
        Vladimir Lypak <vladimir.lypak@gmail.com>,
        <linux-kernel@vger.kernel.org>,
        Marijn Suijten <marijn.suijten@somainline.org>,
        Konrad Dybcio <konrad.dybcio@somainline.org>,
        Martin Botka <martin.botka@somainline.org>
References: <1646242056-2456-1-git-send-email-quic_akhilpo@quicinc.com>
 <20220302225551.v1.7.I55e39e28375b64455d1605f67453d5e91b0c2710@changeid>
 <373491a2-0fa5-0326-29cd-1650f86202d4@collabora.com>
From:   Akhil P Oommen <quic_akhilpo@quicinc.com>
In-Reply-To: <373491a2-0fa5-0326-29cd-1650f86202d4@collabora.com>
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On 3/3/2022 2:51 PM, AngeloGioacchino Del Regno wrote:
> Il 02/03/22 18:27, Akhil P Oommen ha scritto:
>> Retry infinitely on resume failure because there is nothing much we can
>> do if GPU is not ON. Also, this helps us to avoid checking for the
>> return value of pm_runtime_get() to see if GPU is ON.
>>
>> Signed-off-by: Akhil P Oommen <quic_akhilpo@quicinc.com>
>> ---
>>
>>   drivers/gpu/drm/msm/adreno/adreno_device.c | 10 +++++++++-
>>   1 file changed, 9 insertions(+), 1 deletion(-)
>>
>> diff --git a/drivers/gpu/drm/msm/adreno/adreno_device.c 
>> b/drivers/gpu/drm/msm/adreno/adreno_device.c
>> index 89cfd84..abcc553 100644
>> --- a/drivers/gpu/drm/msm/adreno/adreno_device.c
>> +++ b/drivers/gpu/drm/msm/adreno/adreno_device.c
>> @@ -603,8 +603,16 @@ static const struct of_device_id dt_match[] = {
>>   static int adreno_resume(struct device *dev)
>>   {
>>       struct msm_gpu *gpu = dev_to_gpu(dev);
>> +    int ret;
>> +
>> +    /* What hope do we have for the future if we can't turn ON gpu */
>
> Hello Akhil,
>
> the hope for the future would be to at least not lock up everything with
> an infinite loop, so, please change this to have a limited amount of 
> retries.
>
> My guess would be that a maximum of 10 is already a lot of retries, but
> feel free to choose an appropriate number.

Thanks for the feedback, Angelo. I will revisit this.

-Akhil.
>
> Regards,
> Angelo
>
>> +    while (true) {
>> +        ret = gpu->funcs->pm_resume(gpu);
>> +        if (!ret)
>> +            break;
>> +    }
>>   -    return gpu->funcs->pm_resume(gpu);
>> +    return 0;
>>   }
>>     static int active_submits(struct msm_gpu *gpu)
>
>