linux-kernel - Re: [PATCH v3 2/8] drm/msm: Take single rpm refcount on behalf of all submits

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <f08be233-77ae-f645-df88-d264f2336725@quicinc.com>
Date:   Mon, 1 Aug 2022 20:05:53 +0530
From:   Akhil P Oommen <quic_akhilpo@...cinc.com>
To:     Rob Clark <robdclark@...il.com>
CC:     freedreno <freedreno@...ts.freedesktop.org>,
        <dri-devel@...ts.freedesktop.org>, <linux-arm-msm@...r.kernel.org>,
        "Bjorn Andersson" <bjorn.andersson@...aro.org>,
        Jordan Crouse <jordan@...micpenguin.net>,
        Jonathan Marek <jonathan@...ek.ca>,
        "Douglas Anderson" <dianders@...omium.org>,
        Matthias Kaehlcke <mka@...omium.org>,
        Abhinav Kumar <quic_abhinavk@...cinc.com>,
        Daniel Vetter <daniel@...ll.ch>,
        David Airlie <airlied@...ux.ie>,
        Dmitry Baryshkov <dmitry.baryshkov@...aro.org>,
        Sean Paul <sean@...rly.run>, <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH v3 2/8] drm/msm: Take single rpm refcount on behalf of all
 submits

On 8/1/2022 3:45 AM, Rob Clark wrote:
> On Sun, Jul 31, 2022 at 9:33 AM Akhil P Oommen <quic_akhilpo@...cinc.com> wrote:
>> On 7/31/2022 9:26 PM, Rob Clark wrote:
>>> On Sat, Jul 30, 2022 at 2:41 AM Akhil P Oommen <quic_akhilpo@...cinc.com> wrote:
>>>> Instead of separate refcount for each submit, take single rpm refcount
>>>> on behalf of all the submits. This makes it easier to drop the rpm
>>>> refcount during recovery in an upcoming patch.
>>>>
>>>> Signed-off-by: Akhil P Oommen <quic_akhilpo@...cinc.com>
>>>> ---
>>>>
>>>> (no changes since v1)
>>> I see no earlier version of this patch?
My bad, that is incorrect. This is a new patch included in the current 
series.

-Akhil.
>>>
>>>>    drivers/gpu/drm/msm/msm_gpu.c | 12 ++++++++----
>>>>    1 file changed, 8 insertions(+), 4 deletions(-)
>>>>
>>>> diff --git a/drivers/gpu/drm/msm/msm_gpu.c b/drivers/gpu/drm/msm/msm_gpu.c
>>>> index c8cd9bf..e1dd3cc 100644
>>>> --- a/drivers/gpu/drm/msm/msm_gpu.c
>>>> +++ b/drivers/gpu/drm/msm/msm_gpu.c
>>>> @@ -663,11 +663,12 @@ static void retire_submit(struct msm_gpu *gpu, struct msm_ringbuffer *ring,
>>>>           mutex_lock(&gpu->active_lock);
>>>>           gpu->active_submits--;
>>>>           WARN_ON(gpu->active_submits < 0);
>>>> -       if (!gpu->active_submits)
>>>> +       if (!gpu->active_submits) {
>>>>                   msm_devfreq_idle(gpu);
>>>> -       mutex_unlock(&gpu->active_lock);
>>>> +               pm_runtime_put_autosuspend(&gpu->pdev->dev);
>>>> +       }
>>>>
>>>> -       pm_runtime_put_autosuspend(&gpu->pdev->dev);
>>>> +       mutex_unlock(&gpu->active_lock);
>>>>
>>>>           msm_gem_submit_put(submit);
>>>>    }
>>>> @@ -756,14 +757,17 @@ void msm_gpu_submit(struct msm_gpu *gpu, struct msm_gem_submit *submit)
>>>>
>>>>           /* Update devfreq on transition from idle->active: */
>>>>           mutex_lock(&gpu->active_lock);
>>>> -       if (!gpu->active_submits)
>>>> +       if (!gpu->active_submits) {
>>>> +               pm_runtime_get(&gpu->pdev->dev);
>>>>                   msm_devfreq_active(gpu);
>>>> +       }
>>>>           gpu->active_submits++;
>>>>           mutex_unlock(&gpu->active_lock);
>>>>
>>>>           gpu->funcs->submit(gpu, submit);
>>>>           gpu->cur_ctx_seqno = submit->queue->ctx->seqno;
>>>>
>>>> +       pm_runtime_put(&gpu->pdev->dev);
>>> this looks unbalanced?
>> There is another pm_runtime_get_sync at the top of this function. Just
>> before hw_init().
>> https://elixir.bootlin.com/linux/v5.19-rc8/source/drivers/gpu/drm/msm/msm_gpu.c#L737
> oh, right.. sorry, I was looking at my local stack of WIP patches
> which went the opposite direction and moved the runpm into just
> msm_job_run().. I'll drop that one
>
> BR,
> -R
>
>> -Akhil.
>>> BR,
>>> -R
>>>
>>>>           hangcheck_timer_reset(gpu);
>>>>    }
>>>>
>>>> --
>>>> 2.7.4
>>>>