Re: [PATCH v3 09/17] media: i2c: os05b10: update pixel rate on 10/12-bit mode switch

[Tarang Raval]

Hi Jai,

Thanks for the review.

> Quoting Jai Luthra (2026-07-22 11:47:49)
> > Quoting Tarang Raval (2026-07-19 01:39:00)
> > > After adding 12-bit RAW support, the pixel rate depends on the selected
> > > mode bpp. Store the V4L2_CID_PIXEL_RATE control pointer and update its
> > > range/value when the mode changes so 10/12-bit switching reports the
> > > correct pixel rate.
> > >
> >
> > Link frequency (output bus rate) and Pixel rate (sensor internal readout)
> > can often be independent of each other. It would be good to verify that in
> > the sensor documentation.
> >
> > A quick test would be different bpp and the same HTS/VTS and frame size
> > registers if you get the same frame rate, it's likely that the sensor's
> > internal PIXEL_RATE doesn't change due to bpp.
> >
>
> If this sensor indeed operates on different pixel rates just because of the
> output width, I would suggest you squash this to the prior patch which
> introduced the 12 bit support.

I ran the quick test you suggested.

Both 10-bit and 12-bit were tested at 2592x1944, using the same HTS
(shared register list), and I explicitly forced VTS to be identical
between the two run

Measured actual streamed frame rate with v4l2-ctl --stream-mmap in both
cases:

  10-bit, 2592x1944, vts=2006: 30.01 fps
  12-bit, 2592x1944, vts=2006: 30.01 fps

Frame rate is identical. So it looks like the sensor's internal readout
timing doesn't depend on bit depth at all, HTS/VTS alone determine the
real frame rate, and bpp only affects how pixels are packed onto the MIPI
bus, not how fast they're read out.

Best Regards,
Tarang