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Date: Thu, 10 Oct 2019 08:40:29 +0300
From: Andy Shevchenko <andy.shevchenko@...il.com>
To: Stuart Hayes <stuart.w.hayes@...il.com>
Cc: Bjorn Helgaas <bhelgaas@...gle.com>,
Austin Bolen <austin_bolen@...l.com>,
Keith Busch <keith.busch@...el.com>,
Alexandru Gagniuc <mr.nuke.me@...il.com>,
"Rafael J . Wysocki" <rafael.j.wysocki@...el.com>,
Mika Westerberg <mika.westerberg@...ux.intel.com>,
"Gustavo A . R . Silva" <gustavo@...eddedor.com>,
Sinan Kaya <okaya@...nel.org>,
Oza Pawandeep <poza@...eaurora.org>, linux-pci@...r.kernel.org,
Linux Kernel Mailing List <linux-kernel@...r.kernel.org>,
Lukas Wunner <lukas@...ner.de>
Subject: Re: [PATCH 2/3] PCI: pciehp: Wait for PDS if in-band presence is disabled
On Thu, Oct 10, 2019 at 8:37 AM Andy Shevchenko
<andy.shevchenko@...il.com> wrote:
> On Wed, Oct 9, 2019 at 11:05 PM Stuart Hayes <stuart.w.hayes@...il.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
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