ohci-pci: add qemu quirk
authorGerd Hoffmann <kraxel@redhat.com>
Mon, 20 Mar 2017 08:11:49 +0000 (09:11 +0100)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Thu, 25 May 2017 13:44:36 +0000 (15:44 +0200)
commitfc6b678ab1d47085ee0ab3fae4d5289959b45552
treebd9788be9ab6388611192b1b304fb0e7fdd711ca
parent809ae061d998359783c1bb0c52bba14f4a6397c4
ohci-pci: add qemu quirk

commit 21a60f6e65181cad64fd66ccc8080d413721ba27 upstream.

On a loaded virtualization host (dozen guests booting at the same time)
it may happen that the ohci controller emulation doesn't manage to do
timely frame processing, with the result that the io watchdog fires and
considers the controller being dead, even though it's only the emulation
being unusual slow due to the load peak.

So, add a quirk for qemu and don't use the watchdog in case we figure we
are running on emulated ohci.  The virtual ohci controller masquerades
as apple ohci controller, but we can identify it by subsystem id.

Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
drivers/usb/host/ohci-hcd.c
drivers/usb/host/ohci-pci.c
drivers/usb/host/ohci.h