An otherwise correct cleanup patch from Dan Carpenter turned a broken failure handling from a feature patch by Hans Verkuil into a kernel Oops, so bisection points to commit 7af35b0addbc ("drm/kirin: Checking for IS_ERR() instead of NULL") rather than 3b1b975003e4 ("drm: adv7511/33: add HDMI CEC support").
I've managed to piece together several partial problems, though I'm still struggling with the bigger picture:
adv7511_probe() registers a drm_bridge structure that was allocated with devm_kzalloc(). It calls adv7511_cec_init(), which fails for an unknown reason, which in turn triggers the registered structure to be removed.
Elsewhere, kirin_drm_platform_probe() gets called, which calls of_graph_get_remote_node(), and that returns NULL. Before Dan's patch we would go on with a NULL pointer here and register that, now kirin_drm_platform_probe() fails with -ENODEV.
In a third driver, dsi_parse_dt() calls drm_of_find_panel_or_bridge(), which after not finding a panel goes on to call of_drm_find_bridge(), and that crashes due to the earlier list corruption.
This addresses the first issue by making sure that adv7511_probe() does not leave behind any corrupted list entries. This should get the system back to boot but needs testing. From my understanding, there is at least one more bug that needs to be resolved to actually get everything to work again.
Reported-by: Naresh Kamboju naresh.kamboju@linaro.org Cc: Xinliang Liu xinliang.liu@linaro.org Cc: Dan Carpenter dan.carpenter@oracle.com Cc: Sean Paul seanpaul@chromium.org Cc: Hans Verkuil hans.verkuil@cisco.com Cc: Archit Taneja architt@codeaurora.org Link: https://bugs.linaro.org/show_bug.cgi?id=3345 Link: https://lkft.validation.linaro.org/scheduler/job/48017#L3551 Fixes: 7af35b0addbc ("drm/kirin: Checking for IS_ERR() instead of NULL") Fixes: 3b1b975003e4 ("drm: adv7511/33: add HDMI CEC support") Signed-off-by: Arnd Bergmann arnd@arndb.de --- Untested so far, this is what I came up with after reading the WARN_ON log from a modified kernel.
Naresh, can you give this one a go?
Hans and others, can you review in the meantime?
Signed-off-by: Arnd Bergmann arnd@arndb.de --- drivers/gpu/drm/bridge/adv7511/adv7511_drv.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/bridge/adv7511/adv7511_drv.c b/drivers/gpu/drm/bridge/adv7511/adv7511_drv.c index 0e14f1572d05..93d1ecafe8fa 100644 --- a/drivers/gpu/drm/bridge/adv7511/adv7511_drv.c +++ b/drivers/gpu/drm/bridge/adv7511/adv7511_drv.c @@ -1204,7 +1204,7 @@ static int adv7511_probe(struct i2c_client *i2c, const struct i2c_device_id *id) #ifdef CONFIG_DRM_I2C_ADV7511_CEC ret = adv7511_cec_init(dev, adv7511, offset); if (ret) - goto err_unregister_cec; + goto err_unregister_bridge; #else regmap_write(adv7511->regmap, ADV7511_REG_CEC_CTRL + offset, ADV7511_CEC_CTRL_POWER_DOWN); @@ -1212,6 +1212,11 @@ static int adv7511_probe(struct i2c_client *i2c, const struct i2c_device_id *id)
return 0;
+#ifdef CONFIG_DRM_I2C_ADV7511_CEC +err_unregister_bridge: + adv7511_audio_exit(adv7511); + drm_bridge_remove(&adv7511->bridge); +#endif err_unregister_cec: i2c_unregister_device(adv7511->i2c_cec); if (adv7511->cec_clk)