Re: [PATCH 2/3] media: i2c: imx219: Serialize during stream start/stop

From: "Lad, Prabhakar" <prabhakar.csengg@gmail.com>
To: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Cc: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>,
	Dave Stevenson <dave.stevenson@raspberrypi.com>,
	Mauro Carvalho Chehab <mchehab@kernel.org>,
	Pavel Machek <pavel@denx.de>,
	Andrey Konovalov <andrey.konovalov@linaro.org>,
	Sakari Ailus <sakari.ailus@linux.intel.com>,
	Jacopo Mondi <jacopo@jmondi.org>,
	Hans Verkuil <hverkuil-cisco@xs4all.nl>,
	linux-media <linux-media@vger.kernel.org>,
	LKML <linux-kernel@vger.kernel.org>,
	Linux-Renesas <linux-renesas-soc@vger.kernel.org>,
	Biju Das <biju.das.jz@bp.renesas.com>
Subject: Re: [PATCH 2/3] media: i2c: imx219: Serialize during stream start/stop
Date: Wed, 10 Mar 2021 12:46:39 +0000	[thread overview]
Message-ID: <CA+V-a8vPm7EM=MoxRt1nXnvpVVL5vQvSupd79GRNaGULpxS-kQ@mail.gmail.com> (raw)
In-Reply-To: <YEi+FBRbXBJch1DM@pendragon.ideasonboard.com>

Hi Laurent,

Thank you for the review.

On Wed, Mar 10, 2021 at 12:40 PM Laurent Pinchart
<laurent.pinchart@ideasonboard.com> wrote:
>
> Hi Prabhakar,
>
> Thank you for the patch.
>
> On Wed, Mar 10, 2021 at 12:20:13PM +0000, Lad Prabhakar wrote:
> > Serialize during stream start/stop in suspend/resume callbacks.
>
> Could you please explain why this is needed ?
>
The streaming variable in this driver has serialized access, but this
wasn't taken care during suspend/resume callbacks.

Cheers,
Prabhakar

> > Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
> > ---
> >  drivers/media/i2c/imx219.c | 5 +++++
> >  1 file changed, 5 insertions(+)
> >
> > diff --git a/drivers/media/i2c/imx219.c b/drivers/media/i2c/imx219.c
> > index f0cf1985a4dc..87c021de1460 100644
> > --- a/drivers/media/i2c/imx219.c
> > +++ b/drivers/media/i2c/imx219.c
> > @@ -1172,8 +1172,10 @@ static int __maybe_unused imx219_suspend(struct device *dev)
> >       struct v4l2_subdev *sd = dev_get_drvdata(dev);
> >       struct imx219 *imx219 = to_imx219(sd);
> >
> > +     mutex_lock(&imx219->mutex);
> >       if (imx219->streaming)
> >               imx219_stop_streaming(imx219);
> > +     mutex_unlock(&imx219->mutex);
> >
> >       return 0;
> >  }
> > @@ -1184,11 +1186,13 @@ static int __maybe_unused imx219_resume(struct device *dev)
> >       struct imx219 *imx219 = to_imx219(sd);
> >       int ret;
> >
> > +     mutex_lock(&imx219->mutex);
> >       if (imx219->streaming) {
> >               ret = imx219_start_streaming(imx219);
> >               if (ret)
> >                       goto error;
> >       }
> > +     mutex_unlock(&imx219->mutex);
> >
> >       return 0;
> >
> > @@ -1197,6 +1201,7 @@ static int __maybe_unused imx219_resume(struct device *dev)
> >       imx219->streaming = false;
> >       __v4l2_ctrl_grab(imx219->vflip, false);
> >       __v4l2_ctrl_grab(imx219->hflip, false);
> > +     mutex_unlock(&imx219->mutex);
> >
> >       return ret;
> >  }
>
> --
> Regards,
>
> Laurent Pinchart