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SubjectRe: [PATCH 2/3] PCI: pciehp: Wait for PDS if in-band presence is disabled
On Thu, Oct 10, 2019 at 12:40 AM Andy Shevchenko
<andy.shevchenko@gmail.com> wrote:
>
> On Thu, Oct 10, 2019 at 8:37 AM Andy Shevchenko
> <andy.shevchenko@gmail.com> wrote:
> > On Wed, Oct 9, 2019 at 11:05 PM Stuart Hayes <stuart.w.hayes@gmail.com> wrote:
>
> > > +static void pcie_wait_for_presence(struct pci_dev *pdev)
> > > +{
> > > + int timeout = 1250;
>
> > > + bool pds;
>
> Also this is redundant. Just use the following outside the loop
>
> if (!retries)
> pc_info(...);
>
> .
>
> > > + u16 slot_status;
> > > +
> > > + while (true) {
> > > + pcie_capability_read_word(pdev, PCI_EXP_SLTSTA, &slot_status);
> > > + pds = !!(slot_status & PCI_EXP_SLTSTA_PDS);
> > > + if (pds || timeout <= 0)
> > > + break;
> > > + msleep(10);
> > > + timeout -= 10;
> > > + }
> >
> > Can we avoid infinite loops? They are hard to parse (in most cases,
> > and especially when it's a timeout loop)
> >
> > unsigned int retries = 125; // 1250 ms
> >
> > do {
> > ...
> > } while (--retries);
> >
> > > +
> > > + if (!pds)
> > > + pci_info(pdev, "Presence Detect state not set in 1250 msec\n");
> > > +}
> >
> > --
> > With Best Regards,
> > Andy Shevchenko
>
>
>
> --
> With Best Regards,
> Andy Shevchenko

Thank you for the feedback! An infinite loop is used several other places in
this driver--this keeps the style similar. I can change it as you suggest,
though, if that would be preferable to consistency.

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