On Wed, May 08, 2024 at 05:34:57PM GMT, Dan Carpenter wrote:
> On Wed, May 08, 2024 at 03:22:49PM +0100, Diogo Ivo wrote:
> > Hello Dan,
> >
> > On Wed, May 08, 2024 at 10:53:05AM GMT, Dan Carpenter wrote:
> > > Hello Diogo Ivo,
> > >
> > > Commit 27ffe4ff0b33 ("usb: typec: ucsi: Only enable supported
> > > notifications") from Mar 27, 2024 (linux-next), leads to the
> > > following Smatch static checker warning:
> > >
> > > drivers/usb/typec/ucsi/ucsi.c:1671 ucsi_get_supported_notifications()
> > > warn: was expecting a 64 bit value instead of '((((1))) << (24))'
> > >
> > > drivers/usb/typec/ucsi/ucsi.c
> > > 1665 static u64 ucsi_get_supported_notifications(struct ucsi *ucsi)
> > > 1666 {
> > > 1667 u8 features = ucsi->cap.features;
> > > 1668 u64 ntfy = UCSI_ENABLE_NTFY_ALL;
> > > 1669
> > > 1670 if (!(features & UCSI_CAP_ALT_MODE_DETAILS))
> > > --> 1671 ntfy &= ~UCSI_ENABLE_NTFY_CAM_CHANGE;
> > >
> > > ntfy is a u64 but UCSI_ENABLE_NTFY_CAM_CHANGE is unsigned long. So on
> > > a 32 bit system this will clear the high 32 bits. So far as I can see
> > > ntfy should just be a u32. Either way, the types should match.
> > > BIT_ULL() is the way to do that if it really needs to be a u64.
> >
> > In my view this variable really should be a u64 and the definitions of
> > the UCSI_ENABLE_NTFY_* need to be changed to BIT_ULL(). This is due to
> > UCSI versions 2.0 and up definining a new notification on bit 33, crossing
> > the u32 barrier. My suggestion for addressing this is sending two
> > patches, one for changing BIT() -> BIT_ULL() and adding the missing
> > define for the notification of bit 33 and a separate patch to handle
> > this new notification bit in ucsi_get_supported_notifications()/ucsi_init().
> >
> > Thank you for the report and please let me know if this sounds
> > reasonable, or if it would be better to split the changes in another
> > way.
>
> Yes, this sounds reasonable to me. I don't know the hardware at all and
> didn't know you were planning to add a BIT(33).
To be honest this was not something I had thought about and I looked
into it after seeing your report; if this extra notification was not
there the best solution would probably be to use u32.
Best regards,
Diogo
