Re: [PATCH 2/3] PCI: pciehp: Wait for PDS if in-band presence is disabled
From: Andy Shevchenko
Date: Thu Oct 10 2019 - 01:40:50 EST
On Thu, Oct 10, 2019 at 8:37 AM Andy Shevchenko
<andy.shevchenko@xxxxxxxxx> wrote:
> On Wed, Oct 9, 2019 at 11:05 PM Stuart Hayes <stuart.w.hayes@xxxxxxxxx> 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