[PATCH] Fix USB suspend/resume crasher

[Benjamin Herrenschmidt]

> Unfortunately with this patch the EHCI controller in my box (Asus L5D,
> x86-64 kernel) does not resume from suspend.  Appended is the relevant
> snippet from the serial console log (EHCI is the only device using IRQ #5).

Hrm... let me see... You are getting an interrupt for EHCI after it has
been resumed, so it should work.

 /me double-checks the patch

> ehci_hcd 0000:00:02.2: lost power, restarting

Hrm... I can't find that line in the code...

 /me rechecks with david's other patches

Ah ... I see it. There might have been some screwup between david's
patch and mine.

Make sure that 

       set_bit(HCD_FLAG_HW_ACCESSIBLE, &hcd->flags);

Is still done before anything else in ehci_pci_resume(). It may be worth
following it with a memory barrier actually... just in case (due to the
absence of locks in that area).

Ben.