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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, 23 Mar 2017 07:13:21 +0000 (08:13 +0100)
commit21a60f6e65181cad64fd66ccc8080d413721ba27
treed28050eba5889bbfff01052dd4a88223de7db4c4
parentd3d6ef1fb908b286a610fe063613e519bc50178b
ohci-pci: add qemu quirk

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>
Cc: stable <stable@vger.kernel.org>
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