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Message-ID: <20240809132624.GB1435@pendragon.ideasonboard.com>
Date: Fri, 9 Aug 2024 16:26:24 +0300
From: Laurent Pinchart <laurent.pinchart@...asonboard.com>
To: Changhuang Liang <changhuang.liang@...rfivetech.com>
Cc: Mauro Carvalho Chehab <mchehab@...nel.org>,
Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
Hans Verkuil <hverkuil-cisco@...all.nl>,
Jack Zhu <jack.zhu@...rfivetech.com>,
"linux-media@...r.kernel.org" <linux-media@...r.kernel.org>,
"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
"linux-staging@...ts.linux.dev" <linux-staging@...ts.linux.dev>
Subject: Re: 回复: [PATCH] staging: media:
starfive: Add multiple resolution support
On Fri, Aug 09, 2024 at 12:12:01PM +0000, Changhuang Liang wrote:
> Hi, Laurent
>
> Thanks for your comments.
>
> > Hi Changhuang,
> >
> > Thank you for the patch.
> >
> > On Fri, Apr 19, 2024 at 01:19:55AM -0700, Changhuang Liang wrote:
> > > Add multiple resolution support for video "capture_raw" device.
> > > Otherwise it will capture the wrong image data if the width is not 1920.
> > >
> > > Fixes: e080f339c80a ("media: staging: media: starfive: camss: Add
> > > capture driver")
> > >
> > > Signed-off-by: Changhuang Liang <changhuang.liang@...rfivetech.com>
> > > ---
> > > drivers/staging/media/starfive/camss/stf-capture.c | 5 ++++-
> > > 1 file changed, 4 insertions(+), 1 deletion(-)
> > >
> > > diff --git a/drivers/staging/media/starfive/camss/stf-capture.c
> > > b/drivers/staging/media/starfive/camss/stf-capture.c
> > > index ec5169e7b391..9e853ff2596a 100644
> > > --- a/drivers/staging/media/starfive/camss/stf-capture.c
> > > +++ b/drivers/staging/media/starfive/camss/stf-capture.c
> > > @@ -177,9 +177,12 @@ static void stf_channel_set(struct stfcamss_video
> > > *video) {
> > > struct stf_capture *cap = to_stf_capture(video);
> > > struct stfcamss *stfcamss = cap->video.stfcamss;
> > > + struct v4l2_pix_format *pix;
> >
> > This variable can be const as you don't modify the format.
> >
> > > u32 val;
> > >
> > > if (cap->type == STF_CAPTURE_RAW) {
> > > + pix = &video->active_fmt.fmt.pix;
> >
> > And it can be declared and initialized here:
> >
> > const struct v4l2_pix_format *pix = &video->active_fmt.fmt.pix;
> >
> > > +
> > > val = stf_syscon_reg_read(stfcamss, VIN_CHANNEL_SEL_EN);
> > > val &= ~U0_VIN_CHANNEL_SEL_MASK;
> > > val |= CHANNEL(0);
> > > @@ -193,7 +196,7 @@ static void stf_channel_set(struct stfcamss_video *video)
> > > val |= PIXEL_HEIGH_BIT_SEL(0);
> > >
> > > val &= ~U0_VIN_PIX_CNT_END_MASK;
> > > - val |= PIX_CNT_END(IMAGE_MAX_WIDTH / 4 - 1);
> > > + val |= PIX_CNT_END(pix->width / 4 - 1);
> >
> > Is there no need to consider the image height as well ? How does the driver
> > prevent buffer overflows if the sensor sends more data than expected ?
>
> Our hardware will confirm a frame of data through vblank signal, so
> there is no image height configuration.
What happens if the system expects, for instance, a 1920x1080 RAW8
image, and allocates a buffer of of 1920x1080 bytes, but the sensor
outputs more lines ? Does the camera hardware in the SoC offer an option
to prevent buffer overruns ?
> > >
> > > stf_syscon_reg_write(stfcamss, VIN_INRT_PIX_CFG, val);
> > > } else if (cap->type == STF_CAPTURE_YUV) {
--
Regards,
Laurent Pinchart
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