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Date:   Fri, 21 Jul 2023 14:18:54 +0200
From:   Alain Volmat <alain.volmat@foss.st.com>
To:     Hans Verkuil <hverkuil@xs4all.nl>
CC:     Benjamin Mugnier <benjamin.mugnier@foss.st.com>,
        Sylvain Petinot <sylvain.petinot@foss.st.com>,
        Mauro Carvalho Chehab <mchehab@kernel.org>,
        <linux-media@vger.kernel.org>, <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH 1/2] media: i2c: st_mipid02: cascade s_stream call to the
 source subdev
Message-ID: <20230721121854.GA1172642@gnbcxd0016.gnb.st.com>
Mail-Followup-To: Hans Verkuil <hverkuil@xs4all.nl>,
        Benjamin Mugnier <benjamin.mugnier@foss.st.com>,
        Sylvain Petinot <sylvain.petinot@foss.st.com>,
        Mauro Carvalho Chehab <mchehab@kernel.org>,
        linux-media@vger.kernel.org, linux-kernel@vger.kernel.org
References: <20230711123211.794838-1-alain.volmat@foss.st.com>
 <20230711123211.794838-2-alain.volmat@foss.st.com>
 <cd0a1ec0-5ab9-dc14-b1ca-c990b062b3c5@xs4all.nl>
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In-Reply-To: <cd0a1ec0-5ab9-dc14-b1ca-c990b062b3c5@xs4all.nl>
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Hi Hans,

On Wed, Jul 19, 2023 at 12:26:37PM +0200, Hans Verkuil wrote:
> On 11/07/2023 14:32, Alain Volmat wrote:
> > Cascade the s_stream call to the source subdev whenever the bridge
> > streaming is enable / disabled.
> > 
> > Signed-off-by: Alain Volmat <alain.volmat@foss.st.com>
> > ---
> >  drivers/media/i2c/st-mipid02.c | 11 +++++++++++
> >  1 file changed, 11 insertions(+)
> > 
> > diff --git a/drivers/media/i2c/st-mipid02.c b/drivers/media/i2c/st-mipid02.c
> > index 906553a28676..703d2f06f552 100644
> > --- a/drivers/media/i2c/st-mipid02.c
> > +++ b/drivers/media/i2c/st-mipid02.c
> > @@ -547,6 +547,13 @@ static int mipid02_stream_disable(struct mipid02_dev *bridge)
> >  	struct i2c_client *client = bridge->i2c_client;
> >  	int ret;
> >  
> > +	if (!bridge->s_subdev)
> > +		goto error;
> 
> I'm getting this compiler warning:
> 
> media-git/drivers/media/i2c/st-mipid02.c: In function 'mipid02_stream_disable':
> media-git/drivers/media/i2c/st-mipid02.c:568:12: warning: 'ret' may be used uninitialized [-Wmaybe-uninitialized]
>   568 |         if (ret)
>       |            ^
> media-git/drivers/media/i2c/st-mipid02.c:548:13: note: 'ret' was declared here
>   548 |         int ret;
>       |             ^~~
> 
> I'm dropping this series, waiting for a v2.

Indeed, this was a real issue.  I added KCFLAGS=-Wmaybe-uninitialized
in my build command line to spot thoses issues from now on.

v2 posted with the fix.

> 
> Regards,
> 
> 	Hans

Regards,
Alain
> 
> > +
> > +	ret = v4l2_subdev_call(bridge->s_subdev, video, s_stream, 0);
> > +	if (ret)
> > +		goto error;
> > +
> >  	/* Disable all lanes */
> >  	ret = mipid02_write_reg(bridge, MIPID02_CLK_LANE_REG1, 0);
> >  	if (ret)
> > @@ -633,6 +640,10 @@ static int mipid02_stream_enable(struct mipid02_dev *bridge)
> >  	if (ret)
> >  		goto error;
> >  
> > +	ret = v4l2_subdev_call(bridge->s_subdev, video, s_stream, 1);
> > +	if (ret)
> > +		goto error;
> > +
> >  	return 0;
> >  
> >  error:
>