drm/bridge: ite-it66121: 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>
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>

diff --git a/drivers/gpu/drm/bridge/ite-it66121.c b/drivers/gpu/drm/bridge/ite-it66121.c
index 35ae3f0..940083e 100644 (file)
--- a/drivers/gpu/drm/bridge/ite-it66121.c
+++ b/drivers/gpu/drm/bridge/ite-it66121.c
@@ -1450,8 +1450,10 @@ 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);