drm/bridge: anx7625: Fix NULL pointer crash when using edp-panel

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

diff --git a/drivers/gpu/drm/bridge/analogix/anx7625.c b/drivers/gpu/drm/bridge/analogix/anx7625.c
index fcf07a0..aded20b 100644 (file)
--- 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);