On Fri, Oct 11, 2019 at 11:51 PM Stuart Hayes <stuart.w.ha...@gmail.com> wrote:
>
> From: Alexandru Gagniuc <mr.nuke...@gmail.com>
>
> When inband presence is disabled, PDS may come up at any time, or not
> at all. PDS being low may indicate that the card is still mating, and
> we could expect contact bounce to bring down the link as well.
>
> It is reasonable to assume that most cards will mate in a hotplug slot
> in about a second. Thus, when we know PDS only reflects out-of-band
> presence, it's worthwhile to wait the extra second or so to make sure
> the card is properly mated before loading the driver, and to prevent
> the hotplug code from disabling a device if the presence detect change
> goes active after the device is enabled.
Thank you!
My comments below.
> +static void pcie_wait_for_presence(struct pci_dev *pdev)
> +{
> + int timeout = 1250;
> + bool pds;
make W=1 will issue a warning. Just remove the line.
> + u16 slot_status;
> +
> + do {
> + pcie_capability_read_word(pdev, PCI_EXP_SLTSTA, &slot_status);
> + if (!!(slot_status & PCI_EXP_SLTSTA_PDS))
> + return;
> + msleep(10);
> + timeout -= 10;
> + } while (timeout > 0);
> +
> + pci_info(pdev, "Presence Detect state not set in 1250 msec\n");
Perhaps ("%d", timeout) ?
> +}
--
With Best Regards,
Andy Shevchenko
