[PATCH AUTOSEL 6.6 05/17] drm/bridge: ite-it66121: use eld_mutex to protect access to connector->eld

[Sasha Levin <sashal@kernel.org>]

From: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>

[ Upstream commit 39ead6e02ea7d19b421e9d42299d4293fed3064e ]

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>
Link: https://patchwork.freedesktop.org/patch/msgid/20241206-drm-connector-eld-mutex-v2-3-c9bce1ee8bea@linaro.org
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/gpu/drm/bridge/ite-it66121.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/gpu/drm/bridge/ite-it66121.c b/drivers/gpu/drm/bridge/ite-it66121.c
index 8f5846b76d594..2381cd1cba879 100644
--- a/drivers/gpu/drm/bridge/ite-it66121.c
+++ b/drivers/gpu/drm/bridge/ite-it66121.c
@@ -1452,8 +1452,10 @@ static int it66121_audio_get_eld(struct device *dev, void *data,
 		dev_dbg(dev, "No connector present, passing empty EDID data");
 		memset(buf, 0, len);
 	} else {
+		mutex_lock(&ctx->connector->eld_mutex);
 		memcpy(buf, ctx->connector->eld,
 		       min(sizeof(ctx->connector->eld), len));
+		mutex_unlock(&ctx->connector->eld_mutex);
 	}
 	mutex_unlock(&ctx->lock);
 
-- 
2.39.5