From: Sakari Ailus <sakari.ailus@linux.intel.com>
To: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Cc: linuxarm@huawei.com, mauro.chehab@huawei.com,
Mauro Carvalho Chehab <mchehab@kernel.org>,
linux-kernel@vger.kernel.org, linux-media@vger.kernel.org
Subject: Re: [PATCH 25/25] media: i2c: ccs-core: fix pm_runtime_get_sync() usage count
Date: Wed, 5 May 2021 14:02:24 +0300 [thread overview]
Message-ID: <20210505110224.GP3@paasikivi.fi.intel.com> (raw)
In-Reply-To: <20210505125700.4a7584ca@coco.lan>
Hi Mauro,
On Wed, May 05, 2021 at 12:57:00PM +0200, Mauro Carvalho Chehab wrote:
> Em Wed, 5 May 2021 13:34:09 +0300
> Sakari Ailus <sakari.ailus@linux.intel.com> escreveu:
>
> > Hi Mauro,
> >
> > Thanks for the patch.
> >
> > On Wed, May 05, 2021 at 11:42:15AM +0200, Mauro Carvalho Chehab wrote:
> > > The pm_runtime_get_sync() internally increments the
> > > dev->power.usage_count without decrementing it, even on errors.
> > >
> > > There is a bug at ccs_pm_get_init(): when this function returns
> > > an error, the stream is not started, and RPM usage_count
> > > should not be incremented. However, if the calls to
> > > v4l2_ctrl_handler_setup() return errors, it will be kept
> > > incremented.
> > >
> > > At ccs_suspend() the best is to replace it by the new
> > > pm_runtime_resume_and_get(), introduced by:
> > > commit dd8088d5a896 ("PM: runtime: Add pm_runtime_resume_and_get to deal with usage counter")
> > > in order to properly decrement the usage counter automatically,
> > > in the case of errors.
> > >
> > > Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
> >
> > Could you add Fixes: line and Cc: stable?
>
> Sure. See the fixes one enclosed.
>
> > The patch that breaks this is 96e3a6b92f23a .
> >
> > It would be better to fix the bug first so the patch to the stable trees
> > doesn't need special handling.
Please ignore this comment.
> >
> > > ---
> > > drivers/media/i2c/ccs/ccs-core.c | 39 ++++++++++++++++++++------------
> > > 1 file changed, 24 insertions(+), 15 deletions(-)
> > >
> > > diff --git a/drivers/media/i2c/ccs/ccs-core.c b/drivers/media/i2c/ccs/ccs-core.c
> > > index b05f409014b2..04c3ab9e37b4 100644
> > > --- a/drivers/media/i2c/ccs/ccs-core.c
> > > +++ b/drivers/media/i2c/ccs/ccs-core.c
> > > @@ -1880,21 +1880,33 @@ static int ccs_pm_get_init(struct ccs_sensor *sensor)
> > > struct i2c_client *client = v4l2_get_subdevdata(&sensor->src->sd);
> > > int rval;
> > >
> > > + /*
> > > + * It can't use pm_runtime_resume_and_get() here, as the driver
> > > + * relies at the returned value to detect if the device was already
> > > + * active or not.
> > > + */
> > > rval = pm_runtime_get_sync(&client->dev);
> > > - if (rval < 0) {
> > > - pm_runtime_put_noidle(&client->dev);
> > > + if (rval < 0)
> > > + goto error;
> > >
> > > - return rval;
> > > - } else if (!rval) {
> > > - rval = v4l2_ctrl_handler_setup(&sensor->pixel_array->
> > > - ctrl_handler);
> > > - if (rval)
> > > - return rval;
> > > + /* Device was already active, so don't set controls */
> > > + if (rval == 1)
> > > + return 0;
> > >
> > > - return v4l2_ctrl_handler_setup(&sensor->src->ctrl_handler);
> > > - }
> > > + /* Restore V4L2 controls to the suspended device */
> > > + rval = v4l2_ctrl_handler_setup(&sensor->pixel_array->ctrl_handler);
> > > + if (rval)
> > > + goto error;
> > >
> > > + rval = v4l2_ctrl_handler_setup(&sensor->src->ctrl_handler);
> > > + if (rval)
> > > + goto error;
> > > +
> > > + /* Keep PM runtime usage_count incremented on success */
> > > return 0;
> > > +error:
> > > + pm_runtime_put_noidle(&client->dev);
> >
> > This needs to be pm_runtime_put() as the device has been successfully.
>
> Ok.
>
> >
> > > + return rval;
> > > }
> > >
> > > static int ccs_set_stream(struct v4l2_subdev *subdev, int enable)
> > > @@ -3089,12 +3101,9 @@ static int __maybe_unused ccs_suspend(struct device *dev)
> > > bool streaming = sensor->streaming;
> > > int rval;
> > >
> > > - rval = pm_runtime_get_sync(dev);
> > > - if (rval < 0) {
> > > - pm_runtime_put_noidle(dev);
> > > -
> > > + rval = pm_runtime_resume_and_get(dev);
> > > + if (rval < 0)
> > > return rval;
> > > - }
> > >
> > > if (sensor->streaming)
> > > ccs_stop_streaming(sensor);
> >
>
> Thanks,
> Mauro
>
> ---
>
> [PATCH] media: i2c: ccs-core: fix pm_runtime_get_sync() usage count
>
> The pm_runtime_get_sync() internally increments the
> dev->power.usage_count without decrementing it, even on errors.
>
> There is a bug at ccs_pm_get_init(): when this function returns
> an error, the stream is not started, and RPM usage_count
> should not be incremented. However, if the calls to
> v4l2_ctrl_handler_setup() return errors, it will be kept
> incremented.
>
> At ccs_suspend() the best is to replace it by the new
> pm_runtime_resume_and_get(), introduced by:
> commit dd8088d5a896 ("PM: runtime: Add pm_runtime_resume_and_get to deal with usage counter")
> in order to properly decrement the usage counter automatically,
> in the case of errors.
>
> Fixes: 96e3a6b92f23 ("media: smiapp: Avoid maintaining power state information")
> Cc: stable@vger.kernel.org
> Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Acked-by: Sakari Ailus <sakari.ailus@linux.intel.com>
>
> diff --git a/drivers/media/i2c/ccs/ccs-core.c b/drivers/media/i2c/ccs/ccs-core.c
> index b05f409014b2..5ea471fefa3a 100644
> --- a/drivers/media/i2c/ccs/ccs-core.c
> +++ b/drivers/media/i2c/ccs/ccs-core.c
> @@ -1880,21 +1880,33 @@ static int ccs_pm_get_init(struct ccs_sensor *sensor)
> struct i2c_client *client = v4l2_get_subdevdata(&sensor->src->sd);
> int rval;
>
> + /*
> + * It can't use pm_runtime_resume_and_get() here, as the driver
> + * relies at the returned value to detect if the device was already
> + * active or not.
> + */
> rval = pm_runtime_get_sync(&client->dev);
> - if (rval < 0) {
> - pm_runtime_put_noidle(&client->dev);
> + if (rval < 0)
> + goto error;
>
> - return rval;
> - } else if (!rval) {
> - rval = v4l2_ctrl_handler_setup(&sensor->pixel_array->
> - ctrl_handler);
> - if (rval)
> - return rval;
> + /* Device was already active, so don't set controls */
> + if (rval == 1)
> + return 0;
>
> - return v4l2_ctrl_handler_setup(&sensor->src->ctrl_handler);
> - }
> + /* Restore V4L2 controls to the suspended device */
> + rval = v4l2_ctrl_handler_setup(&sensor->pixel_array->ctrl_handler);
> + if (rval)
> + goto error;
>
> + rval = v4l2_ctrl_handler_setup(&sensor->src->ctrl_handler);
> + if (rval)
> + goto error;
> +
> + /* Keep PM runtime usage_count incremented on success */
> return 0;
> +error:
> + pm_runtime_put(&client->dev);
> + return rval;
> }
>
> static int ccs_set_stream(struct v4l2_subdev *subdev, int enable)
>
>
>
>
--
Kind regards,
Sakari Ailus
next prev parent reply other threads:[~2021-05-05 11:02 UTC|newest]
Thread overview: 73+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-05-05 9:41 [PATCH 00/25] Fix some PM runtime issues at the media subsystem Mauro Carvalho Chehab
2021-05-05 9:41 ` [PATCH 01/25] staging: media: rkvdec: fix pm_runtime_get_sync() usage count Mauro Carvalho Chehab
2021-05-05 12:23 ` Jonathan Cameron
2021-05-05 9:41 ` [PATCH 02/25] staging: media: imx7-mipi-csis: " Mauro Carvalho Chehab
2021-05-05 11:06 ` Jonathan Cameron
2021-05-05 11:17 ` Mauro Carvalho Chehab
2021-05-05 13:56 ` Rui Miguel Silva
2021-05-05 14:23 ` Mauro Carvalho Chehab
2021-05-05 9:41 ` [PATCH 03/25] media: venus: Rework error fail recover logic Mauro Carvalho Chehab
2021-05-05 11:05 ` Jonathan Cameron
2021-05-05 9:41 ` [PATCH 04/25] media: s5p_cec: decrement usage count if disabled Mauro Carvalho Chehab
2021-05-05 12:24 ` Jonathan Cameron
2021-05-05 9:41 ` [PATCH 05/25] media: i2c: ccs-core: return the right error code at suspend Mauro Carvalho Chehab
2021-05-05 12:24 ` Jonathan Cameron
2021-05-05 12:51 ` Sakari Ailus
2021-05-05 9:41 ` [PATCH 06/25] media: i2c: imx334: fix the pm runtime get logic Mauro Carvalho Chehab
2021-05-05 11:10 ` Jonathan Cameron
2021-05-05 11:24 ` Mauro Carvalho Chehab
2021-05-05 12:26 ` Jonathan Cameron
2021-05-05 9:41 ` [PATCH 07/25] media: exynos-gsc: don't resume at remove time Mauro Carvalho Chehab
2021-05-05 12:27 ` Jonathan Cameron
2021-05-05 9:41 ` [PATCH 08/25] media: atmel: properly get pm_runtime Mauro Carvalho Chehab
2021-05-05 12:08 ` Jonathan Cameron
2021-06-10 9:04 ` Eugen.Hristev
2021-06-10 9:38 ` Mauro Carvalho Chehab
2021-06-10 12:00 ` Eugen.Hristev
2021-06-16 8:03 ` Mauro Carvalho Chehab
2021-09-06 8:03 ` Mauro Carvalho Chehab
2021-09-06 8:13 ` Eugen.Hristev
2021-09-13 10:26 ` Eugen.Hristev
2021-05-05 9:41 ` [PATCH 09/25] media: hantro: do a PM resume earlier Mauro Carvalho Chehab
2021-05-05 11:34 ` Jonathan Cameron
2021-05-05 13:22 ` Ezequiel Garcia
2021-05-05 13:46 ` Mauro Carvalho Chehab
2021-05-05 14:01 ` Ezequiel Garcia
2021-05-05 14:15 ` Mauro Carvalho Chehab
2021-05-05 9:42 ` [PATCH 10/25] media: marvel-ccic: fix some issues when getting pm_runtime Mauro Carvalho Chehab
2021-05-05 9:42 ` [PATCH 11/25] media: mdk-mdp: fix pm_runtime_get_sync() usage count Mauro Carvalho Chehab
2021-05-05 9:42 ` [PATCH 12/25] media: rcar_fdp1: simplify error check logic at fdp_open() Mauro Carvalho Chehab
2021-05-05 9:48 ` Sergei Shtylyov
2021-05-05 9:42 ` [PATCH 13/25] media: rcar_fdp1: fix pm_runtime_get_sync() usage count Mauro Carvalho Chehab
2021-05-05 12:31 ` Jonathan Cameron
2021-05-05 9:42 ` [PATCH 14/25] media: renesas-ceu: Properly check for PM errors Mauro Carvalho Chehab
2021-05-05 9:56 ` Jacopo Mondi
2021-05-05 9:42 ` [PATCH 15/25] media: s5p: fix pm_runtime_get_sync() usage count Mauro Carvalho Chehab
2021-05-05 12:31 ` Jonathan Cameron
2021-05-05 9:42 ` [PATCH 16/25] media: am437x: " Mauro Carvalho Chehab
2021-05-05 12:32 ` Jonathan Cameron
2021-05-08 13:01 ` Lad, Prabhakar
2021-05-05 9:42 ` [PATCH 17/25] media: sh_vou: " Mauro Carvalho Chehab
2021-05-05 9:42 ` [PATCH 18/25] media: mtk-vcodec: fix PM runtime get logic Mauro Carvalho Chehab
2021-05-05 12:32 ` Jonathan Cameron
2021-05-05 9:42 ` [PATCH 19/25] media: s5p-jpeg: fix pm_runtime_get_sync() usage count Mauro Carvalho Chehab
2021-05-05 12:33 ` Jonathan Cameron
2021-05-05 9:42 ` [PATCH 20/25] media: sti/delta: use pm_runtime_resume_and_get() Mauro Carvalho Chehab
2021-05-05 12:01 ` Jonathan Cameron
2021-05-05 12:33 ` Jonathan Cameron
2021-05-05 9:42 ` [PATCH 21/25] media: sunxi: fix pm_runtime_get_sync() usage count Mauro Carvalho Chehab
2021-05-05 9:42 ` [PATCH 22/25] media: sti/bdisp: " Mauro Carvalho Chehab
2021-05-05 12:34 ` Jonathan Cameron
2021-05-05 9:42 ` [PATCH 23/25] media: exynos4-is: " Mauro Carvalho Chehab
2021-05-05 12:20 ` Jonathan Cameron
2021-05-05 9:42 ` [PATCH 24/25] media: exynos-gsc: " Mauro Carvalho Chehab
2021-05-05 12:34 ` Jonathan Cameron
2021-05-05 9:42 ` [PATCH 25/25] media: i2c: ccs-core: " Mauro Carvalho Chehab
2021-05-05 10:34 ` Sakari Ailus
2021-05-05 10:57 ` Mauro Carvalho Chehab
2021-05-05 10:58 ` Mauro Carvalho Chehab
2021-05-05 12:35 ` Jonathan Cameron
2021-05-05 14:06 ` Mauro Carvalho Chehab
2021-05-05 16:36 ` Jonathan Cameron
2021-05-05 11:02 ` Sakari Ailus [this message]
2021-05-06 15:11 ` [PATCH 00/25] Fix some PM runtime issues at the media subsystem Mauro Carvalho Chehab
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