drm/bridge: anx7625: Drop EDID cache on bridge power off

[ Upstream commit 00ae002116a14c2e6a342c4c9ae080cdbb9b4b21 ]

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: 8bdfc5dae4e3 ("drm/bridge: anx7625: Add anx7625 MIPI DSI/DPI to DP")
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/20240926092931.3870342-2-treapking@chromium.org
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/drivers/gpu/drm/bridge/analogix/anx7625.c b/drivers/gpu/drm/bridge/analogix/anx7625.c
index f895ef1939fa0cbcb38f6893100153b5ee55cbbb..01612d2c034afb40b102d2304708e26e4ab32e9f 100644 (file)
--- a/drivers/gpu/drm/bridge/analogix/anx7625.c
+++ b/drivers/gpu/drm/bridge/analogix/anx7625.c
@@ -1704,6 +1704,8 @@ static int __maybe_unused anx7625_runtime_pm_suspend(struct device *dev)
        mutex_lock(&ctx->lock);
 
        anx7625_stop_dp_work(ctx);
+       if (!ctx->pdata.panel_bridge)
+               anx7625_remove_edid(ctx);
        anx7625_power_standby(ctx);
 
        mutex_unlock(&ctx->lock);