Re: [tip:x86/urgent] x86/quirks: Add early quirk to reset Apple AirPort card

[Yinghai Lu <yinghai@kernel.org>]

On 6/9/16, Lukas Wunner <lukas@wunner.de> wrote:
>
> Well, the PCI core would also scan such a bus twice AFAICS.
> And the performance penalty of scanning it twice seems negligible.
> Early quirks can prevent double execution by setting QFLAG_APPLY_ONCE.
> (Three quirks have set that flag already.)
>
> So I think this shouldn't be a concern.

I don't know. I would like see sth like following, and that is simple enough.

Index: linux-2.6/arch/x86/kernel/early-quirks.c
===================================================================
--- linux-2.6.orig/arch/x86/kernel/early-quirks.c
+++ linux-2.6/arch/x86/kernel/early-quirks.c
@@ -755,10 +755,16 @@ static int __init check_dev_quirk(int nu
        return 0;
 }

+static unsigned char __initdata scanned[256];
 static void __init early_pci_scan_bus(int bus)
 {
        int slot, func;

+       if (scanned[bus])
+               return;
+
+       scanned[bus] = 1;
+
        /* Poor man's PCI discovery */
        for (slot = 0; slot < 32; slot++)
                for (func = 0; func < 8; func++) {