On Tue, May 30, 2023 at 02:39:53PM +0200, Andrew Lunn wrote:
> On Mon, May 29, 2023 at 09:58:02PM -0700, Jakub Kicinski wrote:
> > On Fri, 26 May 2023 14:45:54 +0300 Dan Carpenter wrote:
> > > The "val" variable is used to store error codes from phy_read() so
> > > it needs to be signed for the error handling to work as expected.
> > >
> > > Fixes: 014068dcb5b1 ("net: phy: genphy_loopback: add link speed configuration")
> > > Signed-off-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
> >
> > Is it going to be obvious to PHY-savvy folks that the val passed to
> > phy_read_poll_timeout() must be an int? Is it a very common pattern?
> > My outsider intuition is that since regs are 16b, u16 is reasonable,
> > and more people may make the same mistake.
>
> It is common to get this wrong in general with PHY drivers. Dan
> regularly posts fixes like this soon after a PHY driver patch it
> merged. I really wish we could somehow get the compiler to warn when
> the result from phy_read() is stored into a unsigned type. It would
> save Dan a lot of work.
I don't see these as much as I used. It's maybe once per month. I'm
not sure why, maybe kbuild emails everyone before I see it? GCC will
warn about this with -Wtype-limits. Clang will also trigger a warning.
The Smatch check for this had a bug where it only warned about if
(x < 0) { if x was u32 or larger. I fixed that bug which is why I was
looking at this code. I will push the fix for that in a couple days.
regards,
dan carpenter
