Re: [PATCH v4 1/3] usb: typec: ucsi: Limit read size on v1.2

[Abhishek Pandit-Subedi]

On Fri, Feb 9, 2024 at 6:28 AM Andy Shevchenko
<andriy.shevchenko@xxxxxxxxxxxxxxx> wrote:
>
> On Thu, Feb 08, 2024 at 10:02:38PM -0800, Abhishek Pandit-Subedi wrote:
> > Between UCSI 1.2 and UCSI 2.0, the size of the MESSAGE_IN region was
> > increased from 16 to 256. In order to avoid overflowing reads for older
> > systems, add a mechanism to use the read UCSI version to truncate read
> > sizes on UCSI v1.2.
>
> ...
>
> > +     if (ucsi->version <= UCSI_VERSION_1_2)
> > +             buf_size = min_t(size_t, 16, buf_size);
>
> Please, avoid using min_t(). Here the clamp() can be used.
I think this is likely the 4th time I've been tripped up by an
undocumented practice in this patch series. <linux/minmax.h> says
nothing about avoiding min_t -- why prefer clamp()? Please add the
recommendation here
(https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/include/linux/minmax.h#n10)
and I am more than happy to change it after.

> Shouldn't magic number be defined?
The comment right above this line documents the number.
As this is the only use right now, I don't see a need to make it a
macro/constant yet.

>
> --
> With Best Regards,
> Andy Shevchenko
>
>

Cheers,
Abhishek