Re: [PATCH v4 2/3] media: i2c: Add support for the OV8865 image sensor

[Sakari Ailus]

Hi Paul,

On Tue, Jan 05, 2021 at 10:38:47AM +0100, Paul Kocialkowski wrote:
> Hi Sakari,
> 
> On Mon 04 Jan 21, 14:07, Sakari Ailus wrote:
> > Hi Paul,
> > 
> > On Thu, Dec 31, 2020 at 03:27:01PM +0100, Paul Kocialkowski wrote:
> > > The OV8865 is a 8 Mpx CMOS image sensor producing 3264x2448 at 30 fps.
> > > Other modes (including some with sub-sampling) are available too.
> > > It outputs 10-bit bayer CFA data through a MIPI CSI-2 interface with
> > > up to 4 lanes supported.
> > 
> > I've added the patches to a pull request to Mauro; there appear to still be
> > some checkpatch.pl issues in both of the drivers.
> > 
> > I don't mind the warnings on the assignment or the mutex though. Could you
> > address these in additional patches, please?
> 
> Sorry about that, I realized that I never run checkpatch with --strict
> so I completely missed those.
> 
> I'll fix the cosmetic issues in a following patch.
> 
> Just to clarify one thing:
> #define OV8865_PAD_PK_DRIVE_STRENGTH_2X		(1 << 5)
> #define OV8865_BLC_CTRL1_COL_SHIFT_128		(1 << 4)
> 
> these are not single-bit fields so even though it looks like they should
> use BIT(), this would be incoherent with other possible values, such as:
> #define OV8865_PAD_PK_DRIVE_STRENGTH_3X		(2 << 5)
> #define OV8865_BLC_CTRL1_COL_SHIFT_64		(2 << 4)

Agreed.

You might not assign the top bit, but if you did, the left operand would
have to be unsigned to guarantee the intended result (otherwise it's
undefined).

-- 
Sakari Ailus