Re: `pci_apply_final_quirks()` taking half a second

From: Andy Shevchenko
Date: Wed May 03 2017 - 14:42:22 EST

On Sat, Apr 8, 2017 at 10:06 PM, Bjorn Helgaas <helgaas@xxxxxxxxxx> wrote:
> On Sat, Apr 08, 2017 at 07:00:19PM +0200, David Woodhouse wrote:
>> ...
>> I note it's also reading PCI_CACHE_LINE_SIZE From config space for each
>> device in pci_apply_final_quirks(). How long does that take?
> I don't know, but it's pointless on modern PCIe systems where the
> Cache Line Size has no effect. It'd be really nice if somebody
> cleaned that up and got rid of the read itself and the useless
> messages.

What I can think of is 10ms delay for PM. The laptop might be one of
Intel BayTrails where we have it.
But it's just a guess.

With Best Regards,
Andy Shevchenko