[PATCH 5.18 0420/1095] drm/bridge: anx7625: Fix NULL pointer crash when using edp-panel

Greg Kroah-Hartman
2022-08-15T21:12:09Z

From: Hsin-Yi Wang <hsinyi@chromium.org>

[ Upstream commit dfb02eb6bdf84697dbadd69a7df12db612ce4ed0 ]

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
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
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 060849f8ad8b..c527a3a02eac 100644
--- a/drivers/gpu/drm/bridge/analogix/anx7625.c
+++ b/drivers/gpu/drm/bridge/analogix/anx7625.c
@@ -2651,14 +2651,6 @@ 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;
@@ -2674,6 +2666,15 @@ 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);
--
2.35.1