From 9f8a30f94e0fa670193e4921a63f43b5b4e62de2 Mon Sep 17 00:00:00 2001
From: Hsin-Yi Wang <hsinyi@chromium.org>
Date: Wed, 6 Jul 2022 20:52:53 +0800
Subject: drm/bridge: anx7625: Fix NULL pointer crash when using edp-panel
Git-commit: dfb02eb6bdf84697dbadd69a7df12db612ce4ed0
Patch-mainline: v6.0-rc1
References: jsc#PED-1166 jsc#PED-1168 jsc#PED-1170 jsc#PED-1218 jsc#PED-1220 jsc#PED-1222 jsc#PED-1223 jsc#PED-1225 jsc#PED-2849

Move devm_of_dp_aux_populate_ep_devices() after pm runtime and i2c setup
to avoid NULL pointer crash.

edp-panel probe (generic_edp_panel_probe) calls pm_runtime_get_sync() to
read EDID. At this time, bridge should have pm runtime enabled and i2c
clients ready.

Fixes: adca62ec370c ("drm/bridge: anx7625: Support reading edid through aux channel")
Signed-off-by: Hsin-Yi Wang <hsinyi@chromium.org>
Reviewed-by: Xin Ji <xji@analogixsemi.com>
Signed-off-by: Robert Foss <robert.foss@linaro.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20220706125254.2474095-4-hsinyi@chromium.org
Acked-by: Patrik Jakobsson <pjakobsson@suse.de>
---
 drivers/gpu/drm/bridge/analogix/anx7625.c | 17 +++++++++--------
 1 file changed, 9 insertions(+), 8 deletions(-)

diff --git a/drivers/gpu/drm/bridge/analogix/anx7625.c b/drivers/gpu/drm/bridge/analogix/anx7625.c
index 97b6c9893684..a60306ce6762 100644
--- a/drivers/gpu/drm/bridge/analogix/anx7625.c
+++ b/drivers/gpu/drm/bridge/analogix/anx7625.c
@@ -2590,14 +2590,6 @@ static int anx7625_i2c_probe(struct i2c_client *client,
 	platform->aux.dev = dev;
 	platform->aux.transfer = anx7625_aux_transfer;
 	drm_dp_aux_init(&platform->aux);
-	devm_of_dp_aux_populate_ep_devices(&platform->aux);
-
-	ret = anx7625_parse_dt(dev, pdata);
-	if (ret) {
-		if (ret != -EPROBE_DEFER)
-			DRM_DEV_ERROR(dev, "fail to parse DT : %d\n", ret);
-		goto free_wq;
-	}
 
 	if (anx7625_register_i2c_dummy_clients(platform, client) != 0) {
 		ret = -ENOMEM;
@@ -2613,6 +2605,15 @@ static int anx7625_i2c_probe(struct i2c_client *client,
 	if (ret)
 		goto free_wq;
 
+	devm_of_dp_aux_populate_ep_devices(&platform->aux);
+
+	ret = anx7625_parse_dt(dev, pdata);
+	if (ret) {
+		if (ret != -EPROBE_DEFER)
+			DRM_DEV_ERROR(dev, "fail to parse DT : %d\n", ret);
+		goto free_wq;
+	}
+
 	if (!platform->pdata.low_power_mode) {
 		anx7625_disable_pd_protocol(platform);
 		pm_runtime_get_sync(dev);
-- 
2.38.1