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Date:   Mon, 19 Jun 2023 17:24:58 +0300
From:   Laurent Pinchart <laurent.pinchart@ideasonboard.com>
To:     Sakari Ailus <sakari.ailus@linux.intel.com>
Cc:     Tommaso Merciai <tomm.merciai@gmail.com>,
        jacopo.mondi@ideasonboard.com, martin.hecht@avnet.eu,
        michael.roeder@avnet.eu, linuxfancy@googlegroups.com,
        Mauro Carvalho Chehab <mchehab@kernel.org>,
        Liam Girdwood <lgirdwood@gmail.com>,
        Mark Brown <broonie@kernel.org>,
        Hans Verkuil <hverkuil@xs4all.nl>,
        Marco Felsch <m.felsch@pengutronix.de>,
        Gerald Loacker <gerald.loacker@wolfvision.net>,
        Nicholas Roth <nicholas@rothemail.net>,
        Krzysztof =?utf-8?Q?Ha=C5=82asa?= <khalasa@piap.pl>,
        Linus Walleij <linus.walleij@linaro.org>,
        Benjamin Mugnier <benjamin.mugnier@foss.st.com>,
        Mikhail Rudenko <mike.rudenko@gmail.com>,
        Shawn Tu <shawnx.tu@intel.com>, linux-kernel@vger.kernel.org,
        linux-media@vger.kernel.org
Subject: Re: [PATCH v5 3/3] media: i2c: Add support for alvium camera
Message-ID: <20230619142458.GE10462@pendragon.ideasonboard.com>
References: <20230608083127.545750-1-tomm.merciai@gmail.com>
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On Mon, Jun 19, 2023 at 10:50:10AM +0000, Sakari Ailus wrote:
> On Fri, Jun 09, 2023 at 03:09:41PM +0200, Tommaso Merciai wrote:
> > On Fri, Jun 09, 2023 at 09:17:42AM +0000, Sakari Ailus wrote:
> > > On Thu, Jun 08, 2023 at 10:31:16AM +0200, Tommaso Merciai wrote:
> > > > The Alvium camera is shipped with sensor + isp in the same housing.
> > > > The camera can be equipped with one out of various sensor and abstract
> > > > the user from this. Camera is connected via MIPI CSI-2.
> > > > 
> > > > Most of the camera module features are supported, with the main exception
> > > > being fw update.
> > > > 
> > > > The driver provides all mandatory, optional and recommended V4L2 controls
> > > > for maximum compatibility with libcamera
> > > > 
> > > > References:
> > > >  - https://www.alliedvision.com/en/products/embedded-vision-solutions
> > > > 
> > > > Signed-off-by: Tommaso Merciai <tomm.merciai@gmail.com>
> > > > ---
> > > > Changes since v2:
> > > >  - Removed gpios/clock handling as suggested by LPinchart
> > > >  - Added vcc-ext-in supply support as suggested by LPinchart
> > > >  - Fixed alvium_setup_mipi_fmt funct as suggested by CJAILLET
> > > >  - Removed upside_down/hshake_bit priv data as suggested by CJAILLET
> > > >  - Fixed commit body as suggested by LPinchart
> > > >  - Mv alvium_set_streamon_delay to yalvium_set_lp2hs_delay
> > > >  - Fixed comment on lp2hs prop as suggested by LPinchart
> > > >  - Added pm resume/suspend functs as suggested by LPinchart
> > > >  - Dropped alvium_link_setup/alvium_s_power as suggested by LPinchart
> > > >  - Fixed regs defines as suggested by LPinchart
> > > >  - Fixed typedef as suggested by LPinchart
> > > >  - Dropped bcrm_v/fw_v from priv data as suggested by LPinchart
> > > >  - Now driver use the subdev active state to store the active format and crop
> > > >    as suggested by LPinchart
> > > >  - Dropped alvium_is_csi2/i2c_to_alvium as suggested by LPinchart
> > > > 
> > > > Changes since v3:
> > > >  - Fixed warnings Reported-by: kernel test robot <lkp@intel.com>
> > > > 
> > > > Changes since v4:
> > > >  - Removed print into alvium_get_dt_data for alliedvision,lp2hs-delay-us as
> > > >    suggested by CDooley
> > > > 
> > > >  drivers/media/i2c/Kconfig       |   10 +
> > > >  drivers/media/i2c/Makefile      |    1 +
> > > >  drivers/media/i2c/alvium-csi2.c | 3479 +++++++++++++++++++++++++++++++
> > > >  drivers/media/i2c/alvium-csi2.h |  485 +++++
> > > >  4 files changed, 3975 insertions(+)
> > > >  create mode 100644 drivers/media/i2c/alvium-csi2.c
> > > >  create mode 100644 drivers/media/i2c/alvium-csi2.h

[snip]

> > > > diff --git a/drivers/media/i2c/alvium-csi2.c b/drivers/media/i2c/alvium-csi2.c
> > > > new file mode 100644
> > > > index 000000000000..52c9263075cf
> > > > --- /dev/null
> > > > +++ b/drivers/media/i2c/alvium-csi2.c
> > > > @@ -0,0 +1,3479 @@

[snip]

> > > > +static int alvium_get_img_width_params(struct alvium_dev *alvium)
> > > > +{
> > > > +	struct device *dev = &alvium->i2c_client->dev;
> > > > +	int ret;
> > > > +	u64 val;
> > > > +
> > > > +	if (!alvium->bcrm_addr)
> > > > +		return -EINVAL;
> > > > +
> > > > +	ret = alvium_read(alvium,
> > > > +			  REG_BCRM_IMG_WIDTH_MIN_R,
> > > > +			  &val);
> > > > +	if (ret) {
> > > > +		dev_err(dev, "Fail to read img min width reg\n");
> > > > +		return ret;
> > > > +	}
> > > 
> > > Could you add a macro that assigns the value to the variable (or a struct
> > > field in this case) when the read is successful? Add the print if you think
> > > you need it.
> > 
> > I don't get this comment.
> > Can you explain me better your plan please.
> 
> You have exactly the same pattern repeated over and over in a number of
> functions. I'd like you to add a macro (or a function) that takes what
> varies as arguments, and call that function here. It would reduce a lot of
> the repeated lines code here.
> 
> ...

The best option is to print an error message in alvium_read() and drop
all error messages from the callers.

-- 
Regards,

Laurent Pinchart