[PATCH v2 04/10] drm/amd/display: use eld_mutex to protect access to connector->eld

[Alex Deucher]

On Mon, Dec 16, 2024 at 10:12 AM Dmitry Baryshkov
<dmitry.baryshkov at linaro.org> wrote:
>
> On Mon, 16 Dec 2024 at 16:53, Harry Wentland <harry.wentland at amd.com> wrote:
> >
> >
> >
> > On 2024-12-10 16:20, Dmitry Baryshkov wrote:
> > > On Fri, Dec 06, 2024 at 11:43:07AM +0200, Dmitry Baryshkov wrote:
> > >> Reading access to connector->eld can happen at the same time the
> > >> drm_edid_to_eld() updates the data. Take the newly added eld_mutex in
> > >> order to protect connector->eld from concurrent access.
> > >>
> > >> Reviewed-by: Maxime Ripard <mripard at kernel.org>
> > >> Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov at linaro.org>
> > >> ---
> > >>  drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c | 2 ++
> > >>  1 file changed, 2 insertions(+)
> > >
> > > Harry, Leo, Rodrigo, Alex, Christian, Xinhui, any response to this one
> > > and to the radeon patches? I'd like to be able to pick the series for
> > > drm-misc and these two are not reviewed by you.
> > >
> > >>
> > >> diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
> > >> index 19a58630e774029767bf2a27eb4ddf17e3c21129..04c68c320252b5ce9647f0606fb86fe57f347639 100644
> > >> --- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
> > >> +++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
> > >> @@ -1037,8 +1037,10 @@ static int amdgpu_dm_audio_component_get_eld(struct device *kdev, int port,
> > >>                      continue;
> > >>
> > >>              *enabled = true;
> > >> +            mutex_lock(&connector->eld_mutex);
> > >>              ret = drm_eld_size(connector->eld);
> > >>              memcpy(buf, connector->eld, min(max_bytes, ret));
> > >> +            mutex_unlock(&connector->eld_mutex);
> >
> > All of this is wrapped by the adev->dm.audio_lock mutex. It might
> > be safer to modify the audio_lock mutex so it only guards the
> > aconnector->audio_inst access.
> >
> > But I don't see any way these mutexes would otherwise interact,
> > so this change should be good as-is.
> >
> > Reviewed-by: Harry Wentland <harry.wentland at amd.com>
>
> Would you ack it to merge it through drm-misc? Or would you prefer to
> pick up those two patches after merging drm-misc-next once the rest of
> the series lands?

Merging through drm-misc is fine with me.

Thanks,

Alex

>
> >
> > Harry
> >
> > >>
> > >>              break;
> > >>      }
> > >>
> > >> --
> > >> 2.39.5
> > >>
> > >
> >
>
>
> --
> With best wishes
> Dmitry