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Check the return value to confirm that AUX communication is successful. Fixes: f70ac097a2cf ("drm/mediatek: Add MT8195 Embedded DisplayPort driver") Signed-off-by: Liankun Yang --- drivers/gpu/drm/mediatek/mtk_dp.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) diff --git a/drivers/gpu/drm/mediatek/mtk_dp.c b/drivers/gpu/drm/mediatek/mtk_dp.c index d8796a904eca..3cab65345d1e 100644 --- a/drivers/gpu/drm/mediatek/mtk_dp.c +++ b/drivers/gpu/drm/mediatek/mtk_dp.c @@ -2018,6 +2018,7 @@ static enum drm_connector_status mtk_dp_bdg_detect(struct drm_bridge *bridge) enum drm_connector_status ret = connector_status_disconnected; bool enabled = mtk_dp->enabled; u8 sink_count = 0; + size_t value; if (!mtk_dp->train_info.cable_plugged_in) return ret; @@ -2032,7 +2033,12 @@ static enum drm_connector_status mtk_dp_bdg_detect(struct drm_bridge *bridge) * function, we just need to check the HPD connection to check * whether we connect to a sink device. */ - drm_dp_dpcd_readb(&mtk_dp->aux, DP_SINK_COUNT, &sink_count); + value = drm_dp_dpcd_readb(&mtk_dp->aux, DP_SINK_COUNT, &sink_count); + if (value < 0) { + drm_err(mtk_dp->drm_dev, "Failed to read DP Sink Count: %zd\n", value); + return ret; + } + if (DP_GET_SINK_COUNT(sink_count)) ret = connector_status_connected; -- 2.45.2