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

[Dmitry Baryshkov]

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?

>
> Harry
>
> >>
> >>              break;
> >>      }
> >>
> >> --
> >> 2.39.5
> >>
> >
>


-- 
With best wishes
Dmitry