| Message ID | 1510873179-20786-1-git-send-email-john.stultz@linaro.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
Hi, On 11/17/2017 04:29 AM, John Stultz wrote: > From: Arnd Bergmann <arnd@arndb.de> > > 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 completely fail when the adv7511_cec_init() function fails, > and instead we just disable the CEC feature. This avoids having the > driver entirely fail to load if just the CEC initialization fails. > > 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> > [jstultz: Reworked so when adv7511_cec_init() fails, we disable the feature instead > of disabling the entire driver, which causes graphics to not funciton] > Signed-off-by: John Stultz <john.stultz@linaro.org> > --- > Just wanted to send out my rework of Arnd's patch here. > Feedback would be welcome. > > thanks > -john > > drivers/gpu/drm/bridge/adv7511/adv7511_drv.c | 8 ++++---- > 1 file changed, 4 insertions(+), 4 deletions(-) > > diff --git a/drivers/gpu/drm/bridge/adv7511/adv7511_drv.c b/drivers/gpu/drm/bridge/adv7511/adv7511_drv.c > index 0e14f15..939c3b9 100644 > --- a/drivers/gpu/drm/bridge/adv7511/adv7511_drv.c > +++ b/drivers/gpu/drm/bridge/adv7511/adv7511_drv.c > @@ -1203,12 +1203,12 @@ 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; > #else > - regmap_write(adv7511->regmap, ADV7511_REG_CEC_CTRL + offset, > - ADV7511_CEC_CTRL_POWER_DOWN); > + ret = 1; > #endif > + if (ret) > + regmap_write(adv7511->regmap, ADV7511_REG_CEC_CTRL + offset, > + ADV7511_CEC_CTRL_POWER_DOWN); This would force CEC to be powered off even if adv7511_cec_init() returned 0, right? We wouldn't want that if we want to use CEC on a platform that supports it. Do we know why the call to adv7511_cec_init() is failing on the Hikey board? If it's because there isn't a "cec" clock specified in DT, it's not really a fatal error, it just means that the platform hasn't been set up to support CEC. In that case, we should just power down the CEC block. So, if adv7511_cec_init() would return a -ENOENT, which we could use as a hint to power down CEC. So, maybe something like this?: #ifdef CONFIG_DRM_I2C_ADV7511_CEC ret = adv7511_cec_init(dev, adv7511, offset); if (ret && ret != -ENOENT) goto err_unregister_cec; #endif if (ret) regmap_write(adv7511->regmap, ADV7511_REG_CEC_CTRL + offset, ADV7511_CEC_CTRL_POWER_DOWN); Apart from this, we should also move adv7511_cec_init() up in the probe so that it's called before the drm_bridge is registered. Thanks, Archit > > return 0; > >
On Sun, Nov 26, 2017 at 4:56 AM, Archit Taneja <architt@codeaurora.org> wrote: > > On 11/17/2017 04:29 AM, John Stultz wrote: >> diff --git a/drivers/gpu/drm/bridge/adv7511/adv7511_drv.c >> b/drivers/gpu/drm/bridge/adv7511/adv7511_drv.c >> index 0e14f15..939c3b9 100644 >> --- a/drivers/gpu/drm/bridge/adv7511/adv7511_drv.c >> +++ b/drivers/gpu/drm/bridge/adv7511/adv7511_drv.c >> @@ -1203,12 +1203,12 @@ 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; >> #else >> - regmap_write(adv7511->regmap, ADV7511_REG_CEC_CTRL + offset, >> - ADV7511_CEC_CTRL_POWER_DOWN); >> + ret = 1; >> #endif >> + if (ret) >> + regmap_write(adv7511->regmap, ADV7511_REG_CEC_CTRL + >> offset, >> + ADV7511_CEC_CTRL_POWER_DOWN); > > > This would force CEC to be powered off even if adv7511_cec_init() returned > 0, right? I don't think so. The initent was its only powered off if adv7511_cec_init returns an error or if CONFIG_DRM_I2C_ADV7511_CEC is not set. > Do we know why the call to adv7511_cec_init() is failing on the Hikey board? > If it's > because there isn't a "cec" clock specified in DT, it's not really a fatal > error, it > just means that the platform hasn't been set up to support CEC. In that Yea. I believe this is the case w/ HiKey. I don't have deeply detailed docs on the board so I'm not sure if we will be able to enable that or not (Xinliang/Guodong: Do you know if its possible?). In the meantime though, we shouldn't regress. > case, we > should just power down the CEC block. So, if adv7511_cec_init() would return > a > -ENOENT, which we could use as a hint to power down CEC. So, maybe something > like this?: > > #ifdef CONFIG_DRM_I2C_ADV7511_CEC > ret = adv7511_cec_init(dev, adv7511, offset); > if (ret && ret != -ENOENT) > goto err_unregister_cec; > #endif > if (ret) > regmap_write(adv7511->regmap, ADV7511_REG_CEC_CTRL + offset, > ADV7511_CEC_CTRL_POWER_DOWN); > > Apart from this, we should also move adv7511_cec_init() up in the probe so > that > it's called before the drm_bridge is registered. Hans has since reworked the patch w/ a new version. You might want to check his patches and see if they fit what your imagining. thanks -john
On 11/29/2017 03:02 AM, John Stultz wrote: > On Sun, Nov 26, 2017 at 4:56 AM, Archit Taneja <architt@codeaurora.org> wrote: >> >> On 11/17/2017 04:29 AM, John Stultz wrote: >>> diff --git a/drivers/gpu/drm/bridge/adv7511/adv7511_drv.c >>> b/drivers/gpu/drm/bridge/adv7511/adv7511_drv.c >>> index 0e14f15..939c3b9 100644 >>> --- a/drivers/gpu/drm/bridge/adv7511/adv7511_drv.c >>> +++ b/drivers/gpu/drm/bridge/adv7511/adv7511_drv.c >>> @@ -1203,12 +1203,12 @@ 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; >>> #else >>> - regmap_write(adv7511->regmap, ADV7511_REG_CEC_CTRL + offset, >>> - ADV7511_CEC_CTRL_POWER_DOWN); >>> + ret = 1; >>> #endif >>> + if (ret) >>> + regmap_write(adv7511->regmap, ADV7511_REG_CEC_CTRL + >>> offset, >>> + ADV7511_CEC_CTRL_POWER_DOWN); >> >> >> This would force CEC to be powered off even if adv7511_cec_init() returned >> 0, right? > > I don't think so. The initent was its only powered off if > adv7511_cec_init returns an error or if CONFIG_DRM_I2C_ADV7511_CEC is > not set. > >> Do we know why the call to adv7511_cec_init() is failing on the Hikey board? >> If it's >> because there isn't a "cec" clock specified in DT, it's not really a fatal >> error, it >> just means that the platform hasn't been set up to support CEC. In that > > Yea. I believe this is the case w/ HiKey. I don't have deeply > detailed docs on the board so I'm not sure if we will be able to > enable that or not (Xinliang/Guodong: Do you know if its possible?). > In the meantime though, we shouldn't regress. > >> case, we >> should just power down the CEC block. So, if adv7511_cec_init() would return >> a >> -ENOENT, which we could use as a hint to power down CEC. So, maybe something >> like this?: >> >> #ifdef CONFIG_DRM_I2C_ADV7511_CEC >> ret = adv7511_cec_init(dev, adv7511, offset); >> if (ret && ret != -ENOENT) >> goto err_unregister_cec; >> #endif >> if (ret) >> regmap_write(adv7511->regmap, ADV7511_REG_CEC_CTRL + offset, >> ADV7511_CEC_CTRL_POWER_DOWN); >> >> Apart from this, we should also move adv7511_cec_init() up in the probe so >> that >> it's called before the drm_bridge is registered. > > Hans has since reworked the patch w/ a new version. You might want to > check his patches and see if they fit what your imagining. Yes, I saw Hans's patch after I wrote to you. That patch looks perfect. I'll queue that to the drm-misc repo once it's rebased on 4.15-rc1. Thanks, Archit > > thanks > -john >
On Wed, Nov 29, 2017 at 6:05 AM, Archit Taneja <architt@codeaurora.org> wrote: > On 11/29/2017 03:02 AM, John Stultz wrote: >> On Sun, Nov 26, 2017 at 4:56 AM, Archit Taneja <architt@codeaurora.org> wrote: >>> Apart from this, we should also move adv7511_cec_init() up in the probe >>> so that it's called before the drm_bridge is registered. >> >> >> Hans has since reworked the patch w/ a new version. You might want to >> check his patches and see if they fit what your imagining. > > > Yes, I saw Hans's patch after I wrote to you. That patch looks perfect. I'll > queue that to the drm-misc repo once it's rebased on 4.15-rc1. It would be nice to get it merged into -rc2 if possible, as this currently blocks all of the kselftest regression tracking that we're doing on Hikey, since the arm64 defconfig fails to boot in both mainline and linux-next, see https://bugs.linaro.org/show_bug.cgi?id=3345 Arnd
diff --git a/drivers/gpu/drm/bridge/adv7511/adv7511_drv.c b/drivers/gpu/drm/bridge/adv7511/adv7511_drv.c index 0e14f15..939c3b9 100644 --- a/drivers/gpu/drm/bridge/adv7511/adv7511_drv.c +++ b/drivers/gpu/drm/bridge/adv7511/adv7511_drv.c @@ -1203,12 +1203,12 @@ 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; #else - regmap_write(adv7511->regmap, ADV7511_REG_CEC_CTRL + offset, - ADV7511_CEC_CTRL_POWER_DOWN); + ret = 1; #endif + if (ret) + regmap_write(adv7511->regmap, ADV7511_REG_CEC_CTRL + offset, + ADV7511_CEC_CTRL_POWER_DOWN); return 0;