linux-kernel - Re: [PATCH 6/6] media: ov5640: Consolidate JPEG compression mode setting

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Date:   Tue, 5 Feb 2019 18:08:03 +0200
From:   Sakari Ailus <sakari.ailus@...ux.intel.com>
To:     Chen-Yu Tsai <wens@...e.org>
Cc:     Steve Longerbeam <slongerbeam@...il.com>,
        Mauro Carvalho Chehab <mchehab@...nel.org>,
        Linux Media Mailing List <linux-media@...r.kernel.org>,
        linux-kernel <linux-kernel@...r.kernel.org>,
        Maxime Ripard <maxime.ripard@...tlin.com>
Subject: Re: [PATCH 6/6] media: ov5640: Consolidate JPEG compression mode
 setting

On Tue, Feb 05, 2019 at 09:50:47PM +0800, Chen-Yu Tsai wrote:
> On Tue, Feb 5, 2019 at 4:55 PM Sakari Ailus
> <sakari.ailus@...ux.intel.com> wrote:
> >
> > Hi Chen-Yu,
> >
> > On Fri, Jan 18, 2019 at 04:52:06PM +0800, Chen-Yu Tsai wrote:
> > > The register value lists for all the supported resolution settings all
> > > include a register address/value pair for setting the JPEG compression
> > > mode. With the exception of 1080p (which sets mode 2), all resolutions
> > > use mode 3.
> > >
> > > The only difference between mode 2 and mode 3 is that mode 2 may have
> > > padding data on the last line, while mode 3 does not add padding data.
> > >
> > > As these register values were from dumps of running systems, and the
> > > difference between the modes is quite small, using mode 3 for all
> > > configurations should be OK.
> > >
> > > Signed-off-by: Chen-Yu Tsai <wens@...e.org>
> > > ---
> > >  drivers/media/i2c/ov5640.c | 34 +++++++++++++++++++++++-----------
> > >  1 file changed, 23 insertions(+), 11 deletions(-)
> > >
> > > diff --git a/drivers/media/i2c/ov5640.c b/drivers/media/i2c/ov5640.c
> > > index 1c1dc401c678..3d2c5de73283 100644
> > > --- a/drivers/media/i2c/ov5640.c
> > > +++ b/drivers/media/i2c/ov5640.c
> > > @@ -85,6 +85,7 @@
> > >  #define OV5640_REG_FORMAT_CONTROL00  0x4300
> > >  #define OV5640_REG_VFIFO_HSIZE               0x4602
> > >  #define OV5640_REG_VFIFO_VSIZE               0x4604
> > > +#define OV5640_REG_JPG_MODE_SELECT   0x4713
> >
> > How has this been tested?
> >
> > The register is referred to as "OV5640_REG_JPEG_MODE_SELECT" below. I can
> > fix it if it's just a typo, but please confirm.
> 
> It's a typo. The datasheet uses the abbreviated form, JPG_MODE_SELECT,
> but all the bitfield names are the full JPEG form. I believe I missed
> the other occurrence while fixing up the names to match the datasheet.
> I appologize for not doing a final compile test.

Thanks, and no problem.

-- 
Sakari Ailus
sakari.ailus@...ux.intel.com