[PATCH 2/2] drm/bridge: adv7511: handle regcache_sync() failure on power on

[phucduc.bui@gmail.com]

From: bui duc phuc <phucduc.bui@gmail.com>

regcache_sync() failure in adv7511_power_on() is silently ignored,
leaving the chip marked as powered on even though register
synchronization may not have completed successfully. Log the error
and attempt to power the chip back off on failure, to avoid the
driver believing the chip is fully configured when it may not be.

Signed-off-by: bui duc phuc <phucduc.bui@gmail.com>
---
 drivers/gpu/drm/bridge/adv7511/adv7511_drv.c | 10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/bridge/adv7511/adv7511_drv.c b/drivers/gpu/drm/bridge/adv7511/adv7511_drv.c
index d98a8f7afc7f..3e470366bce0 100644
--- a/drivers/gpu/drm/bridge/adv7511/adv7511_drv.c
+++ b/drivers/gpu/drm/bridge/adv7511/adv7511_drv.c
@@ -367,12 +367,20 @@ static void __adv7511_power_on(struct adv7511 *adv7511)
 
 static void adv7511_power_on(struct adv7511 *adv7511)
 {
+	int ret;
+
 	__adv7511_power_on(adv7511);
 
 	/*
 	 * Most of the registers are reset during power down or when HPD is low.
 	 */
-	regcache_sync(adv7511->regmap);
+	ret = regcache_sync(adv7511->regmap);
+	if (ret) {
+		dev_err(&adv7511->i2c_main->dev,
+			"Failed to sync register cache: %d\n", ret);
+		__adv7511_power_off(adv7511);
+		return;
+	}
 
 	if (adv7511->info->has_dsi)
 		adv7533_dsi_power_on(adv7511);
-- 
2.43.0