| Message ID | 1550416667-9372-1-git-send-email-akinobu.mita@gmail.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | media: ov7740: fix runtime pm initialization | expand |
On 17.02.2019 17:17, Akinobu Mita wrote: > The runtime PM of this device is enabled after v4l2_ctrl_handler_setup(), > and this makes this device's runtime PM usage count a negative value. > > The ov7740_set_ctrl() tries to do something only if the device's runtime > PM usage counter is nonzero. > > ov7740_set_ctrl() > { > if (!pm_runtime_get_if_in_use(&client->dev)) > return 0; > > <do something>; > > pm_runtime_put(&client->dev); > > return ret; > } > > However, the ov7740_set_ctrl() is called by v4l2_ctrl_handler_setup() > while the runtime PM of this device is not yet enabled. In this case, > the pm_runtime_get_if_in_use() returns -EINVAL (!= 0). > > Therefore we can't bail out of this function and the usage count is > decreased by pm_runtime_put() without increment. > > This fixes this problem by enabling the runtime PM of this device before > v4l2_ctrl_handler_setup() so that the ov7740_set_ctrl() is always called > when the runtime PM is enabled. > > Cc: Eugen Hristev <eugen.hristev@microchip.com> > Cc: Wenyou Yang <wenyou.yang@microchip.com> > Cc: Sakari Ailus <sakari.ailus@linux.intel.com> > Cc: Mauro Carvalho Chehab <mchehab@kernel.org> > Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com> > --- > I don't have the ov7740 device, but I saw the same problem with the > mt9m001 device when I was adding the runtime PM support for it. > > Eugen Hristev reported the problem with ov7740. Hi, This fixes my issue with this sensor in latest mediatree For anything's worth, for Atmel ISC + ov7740, with my patch, Tested-by: Eugen Hristev <eugen.hristev@microchip.com> Thanks > > https://www.mail-archive.com/linux-media@vger.kernel.org/msg144540.html > > I suspect that it is related to this runtime PM problem. > > There seems to be the same problem in other devices. I would like to see > if this patch actually fix the ov7740's problem and then propagate other > devices. > > drivers/media/i2c/ov7740.c | 7 +++++-- > 1 file changed, 5 insertions(+), 2 deletions(-) > > diff --git a/drivers/media/i2c/ov7740.c b/drivers/media/i2c/ov7740.c > index 177688a..8835b83 100644 > --- a/drivers/media/i2c/ov7740.c > +++ b/drivers/media/i2c/ov7740.c > @@ -1101,6 +1101,9 @@ static int ov7740_probe(struct i2c_client *client, > if (ret) > return ret; > > + pm_runtime_set_active(&client->dev); > + pm_runtime_enable(&client->dev); > + > ret = ov7740_detect(ov7740); > if (ret) > goto error_detect; > @@ -1123,8 +1126,6 @@ static int ov7740_probe(struct i2c_client *client, > if (ret) > goto error_async_register; > > - pm_runtime_set_active(&client->dev); > - pm_runtime_enable(&client->dev); > pm_runtime_idle(&client->dev); > > return 0; > @@ -1134,6 +1135,8 @@ static int ov7740_probe(struct i2c_client *client, > error_init_controls: > ov7740_free_controls(ov7740); > error_detect: > + pm_runtime_disable(&client->dev); > + pm_runtime_set_suspended(&client->dev); > ov7740_set_power(ov7740, 0); > media_entity_cleanup(&ov7740->subdev.entity); > >
diff --git a/drivers/media/i2c/ov7740.c b/drivers/media/i2c/ov7740.c index 177688a..8835b83 100644 --- a/drivers/media/i2c/ov7740.c +++ b/drivers/media/i2c/ov7740.c @@ -1101,6 +1101,9 @@ static int ov7740_probe(struct i2c_client *client, if (ret) return ret; + pm_runtime_set_active(&client->dev); + pm_runtime_enable(&client->dev); + ret = ov7740_detect(ov7740); if (ret) goto error_detect; @@ -1123,8 +1126,6 @@ static int ov7740_probe(struct i2c_client *client, if (ret) goto error_async_register; - pm_runtime_set_active(&client->dev); - pm_runtime_enable(&client->dev); pm_runtime_idle(&client->dev); return 0; @@ -1134,6 +1135,8 @@ static int ov7740_probe(struct i2c_client *client, error_init_controls: ov7740_free_controls(ov7740); error_detect: + pm_runtime_disable(&client->dev); + pm_runtime_set_suspended(&client->dev); ov7740_set_power(ov7740, 0); media_entity_cleanup(&ov7740->subdev.entity);
The runtime PM of this device is enabled after v4l2_ctrl_handler_setup(), and this makes this device's runtime PM usage count a negative value. The ov7740_set_ctrl() tries to do something only if the device's runtime PM usage counter is nonzero. ov7740_set_ctrl() { if (!pm_runtime_get_if_in_use(&client->dev)) return 0; <do something>; pm_runtime_put(&client->dev); return ret; } However, the ov7740_set_ctrl() is called by v4l2_ctrl_handler_setup() while the runtime PM of this device is not yet enabled. In this case, the pm_runtime_get_if_in_use() returns -EINVAL (!= 0). Therefore we can't bail out of this function and the usage count is decreased by pm_runtime_put() without increment. This fixes this problem by enabling the runtime PM of this device before v4l2_ctrl_handler_setup() so that the ov7740_set_ctrl() is always called when the runtime PM is enabled. Cc: Eugen Hristev <eugen.hristev@microchip.com> Cc: Wenyou Yang <wenyou.yang@microchip.com> Cc: Sakari Ailus <sakari.ailus@linux.intel.com> Cc: Mauro Carvalho Chehab <mchehab@kernel.org> Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com> --- I don't have the ov7740 device, but I saw the same problem with the mt9m001 device when I was adding the runtime PM support for it. Eugen Hristev reported the problem with ov7740. https://www.mail-archive.com/linux-media@vger.kernel.org/msg144540.html I suspect that it is related to this runtime PM problem. There seems to be the same problem in other devices. I would like to see if this patch actually fix the ov7740's problem and then propagate other devices. drivers/media/i2c/ov7740.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-)