drm/amd/display: use eld_mutex to protect access to connector->eld

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@kernel.org>
Reviewed-by: Harry Wentland <harry.wentland@amd.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20241206-drm-connector-eld-mutex-v2-4-c9bce1ee8bea@linaro.org
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>

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 243cee2841312012c3f3999e711018835181b63a..dea640816e190648b6fbec7affdd675f21cbdb9a 100644 (file)
--- 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);
 
                break;
        }