[PATCH AUTOSEL 6.13 22/34] drm/vc4: hdmi: use eld_mutex to protect access to connector->eld

From: Sasha Levin
Date: Sun Jan 26 2025 - 10:08:51 EST


From: Dmitry Baryshkov <dmitry.baryshkov@xxxxxxxxxx>

[ Upstream commit 81a9a93b169a273ccc4a9a1ee56f17e9981d3f98 ]

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@xxxxxxxxxx>
Link: https://patchwork.freedesktop.org/patch/msgid/20241206-drm-connector-eld-mutex-v2-10-c9bce1ee8bea@xxxxxxxxxx
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
drivers/gpu/drm/vc4/vc4_hdmi.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/vc4/vc4_hdmi.c b/drivers/gpu/drm/vc4/vc4_hdmi.c
index e3818c48c9b8c..e86123009c905 100644
--- a/drivers/gpu/drm/vc4/vc4_hdmi.c
+++ b/drivers/gpu/drm/vc4/vc4_hdmi.c
@@ -2193,9 +2193,9 @@ static int vc4_hdmi_audio_get_eld(struct device *dev, void *data,
struct vc4_hdmi *vc4_hdmi = dev_get_drvdata(dev);
struct drm_connector *connector = &vc4_hdmi->connector;

- mutex_lock(&vc4_hdmi->mutex);
+ mutex_lock(&connector->eld_mutex);
memcpy(buf, connector->eld, min(sizeof(connector->eld), len));
- mutex_unlock(&vc4_hdmi->mutex);
+ mutex_unlock(&connector->eld_mutex);

return 0;
}
--
2.39.5