Re: [PATCH v11 8/9] PCI: Split PME state selection into a local static function

[Limonciello, Mario]

On 8/11/2023 3:55 AM, Andy Shevchenko wrote:
> On Thu, Aug 10, 2023 at 11:29:49AM -0500, Limonciello, Mario wrote:
> > On 8/10/2023 11:21 AM, Andy Shevchenko wrote:
> > > On Wed, Aug 09, 2023 at 01:54:52PM -0500, Mario Limonciello wrote:
>
> ...
>
> > > > +static inline pci_power_t pci_get_wake_pme_state(struct pci_dev *dev)
> > > > +{
> > > > +	pci_power_t state = PCI_D3hot;
> > > > +
> > > > +	while (state && !(dev->pme_support & (1 << state)))
> > > > +		state--;
> > > > +
> > > > +	return state;
> > >
> > > Sparse won't be happy about this code (with CF=-D__CHECK_ENDIAN__).
> > >
> > > Basically it's something like
> > >
> > > 	return (__force pci_power_t)fls(dev->pme_support & GENMASK(PCI_D3hot, 0));
> > >
> > > (but double check and test the logic).
> > >
> > > > +}
> > >
> > > ...
> > >
> > > Yeah, I see that is the existing code, perhaps amend it first?
> >
> > Are you sure?
>
> Yes.
>
> Just the original code
>
> drivers/pci/pci.c:2711:60: warning: restricted pci_power_t degrades to integer
> drivers/pci/pci.c:2712:30: warning: restricted pci_power_t degrades to integer
>
>                  /*
>                   * Find the deepest state from which the device can generate
>                   * PME#.
>                   */
> 2711 ==>         while (state && !(dev->pme_support & (1 << state)))
> 2712 ==>                state--;
>
> How is yours different?
>
> > I actually double checked the sparse output using this
> > command before I sent it.
> >
> > make W=1 C=1 CF='-fdiagnostic-prefix -D__CHECK_ENDIAN__' drivers/pci/pci.o
> >
> > I didn't see anything related to the line numbers for this function.
>
> Just in case...
>
> $ gcc --version
> gcc (Debian 12.3.0-5) 12.3.0
>
> $ sparse --version
> 0.6.4 (Debian: 0.6.4-3)
>
> $ make --version
> GNU Make 4.3
> Built for x86_64-pc-linux-gnu

Oh, I see why I wasn't observing it now.  Because it's inline code it's 
processed separately and isn't with the rest of the grouped output from 
2416 through 2922.

drivers/pci/pci.c:2679:52: sparse: warning: restricted pci_power_t 
degrades to integer
drivers/pci/pci.c:2680:22: sparse: warning: restricted pci_power_t 
degrades to integer