drm/sti: hdmi: 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>
Acked-by: Raphael Gallais-Pou <rgallaispou@gmail.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20241206-drm-connector-eld-mutex-v2-9-c9bce1ee8bea@linaro.org
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>

diff --git a/drivers/gpu/drm/sti/sti_hdmi.c b/drivers/gpu/drm/sti/sti_hdmi.c
index 21b46a6465f08afbcaa8fb95f9cf320c85b4bb83..f8bbae6393ef8c0bd1deb75d1e131c1d83c1ebfe 100644 (file)
--- a/drivers/gpu/drm/sti/sti_hdmi.c
+++ b/drivers/gpu/drm/sti/sti_hdmi.c
@@ -1225,7 +1225,9 @@ static int hdmi_audio_get_eld(struct device *dev, void *data, uint8_t *buf, size
        struct drm_connector *connector = hdmi->drm_connector;
 
        DRM_DEBUG_DRIVER("\n");
+       mutex_lock(&connector->eld_mutex);
        memcpy(buf, connector->eld, min(sizeof(connector->eld), len));
+       mutex_unlock(&connector->eld_mutex);
 
        return 0;
 }