drm/bridge: it6505: Drop EDID cache on bridge power off

The bridge might miss the display change events when it's powered off.
This happens when a user changes the external monitor when the system
is suspended and the embedded controller doesn't not wake AP up.

It's also observed that one DP-to-HDMI bridge doesn't work correctly
when there is no EDID read after it is powered on.

Drop the cache to force an EDID read after system resume to fix this.

Fixes: 11feaef69d0c ("drm/bridge: it6505: Add caching for EDID")
Signed-off-by: Pin-yen Lin <treapking@chromium.org>
Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Reviewed-by: Douglas Anderson <dianders@chromium.org>
Signed-off-by: Douglas Anderson <dianders@chromium.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20240926092931.3870342-3-treapking@chromium.org

diff --git a/drivers/gpu/drm/bridge/ite-it6505.c b/drivers/gpu/drm/bridge/ite-it6505.c
index f372c05360f2e2ae87c88fc32c9748550f5c2362..7ff17aa14b01e4d9f626424e065131ae2b195c62 100644 (file)
--- a/drivers/gpu/drm/bridge/ite-it6505.c
+++ b/drivers/gpu/drm/bridge/ite-it6505.c
@@ -3107,6 +3107,8 @@ static __maybe_unused int it6505_bridge_suspend(struct device *dev)
 {
        struct it6505 *it6505 = dev_get_drvdata(dev);
 
+       it6505_remove_edid(it6505);
+
        return it6505_poweroff(it6505);
 }