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>

diff --git a/drivers/usb/host/ohci-hcd.c b/drivers/usb/host/ohci-hcd.c
index da66ad57e37031caa92e545521a944477f028eac..44924824fa414a28dfbf10a715b658e6b493a462 100644 (file)
--- a/drivers/usb/host/ohci-hcd.c
+++ b/drivers/usb/host/ohci-hcd.c
@@ -231,7 +231,8 @@ static int ohci_urb_enqueue (
 
                /* Start up the I/O watchdog timer, if it's not running */
                if (!timer_pending(&ohci->io_watchdog) &&
-                               list_empty(&ohci->eds_in_use)) {
+                               list_empty(&ohci->eds_in_use) &&
+                               !(ohci->flags & OHCI_QUIRK_QEMU)) {
                        ohci->prev_frame_no = ohci_frame_no(ohci);
                        mod_timer(&ohci->io_watchdog,
                                        jiffies + IO_WATCHDOG_DELAY);

diff --git a/drivers/usb/host/ohci-pci.c b/drivers/usb/host/ohci-pci.c
index bb1509675727b374586d61917920578cc7631a45..a84aebe9b0a97880ef1f83a17b483e7586f190b1 100644 (file)
--- a/drivers/usb/host/ohci-pci.c
+++ b/drivers/usb/host/ohci-pci.c
@@ -164,6 +164,15 @@ static int ohci_quirk_amd700(struct usb_hcd *hcd)
        return 0;
 }
 
+static int ohci_quirk_qemu(struct usb_hcd *hcd)
+{
+       struct ohci_hcd *ohci = hcd_to_ohci(hcd);
+
+       ohci->flags |= OHCI_QUIRK_QEMU;
+       ohci_dbg(ohci, "enabled qemu quirk\n");
+       return 0;
+}
+
 /* List of quirks for OHCI */
 static const struct pci_device_id ohci_pci_quirks[] = {
        {
@@ -214,6 +223,13 @@ static const struct pci_device_id ohci_pci_quirks[] = {
                PCI_DEVICE(PCI_VENDOR_ID_ATI, 0x4399),
                .driver_data = (unsigned long)ohci_quirk_amd700,
        },
+       {
+               .vendor         = PCI_VENDOR_ID_APPLE,
+               .device         = 0x003f,
+               .subvendor      = PCI_SUBVENDOR_ID_REDHAT_QUMRANET,
+               .subdevice      = PCI_SUBDEVICE_ID_QEMU,
+               .driver_data    = (unsigned long)ohci_quirk_qemu,
+       },
 
        /* FIXME for some of the early AMD 760 southbridges, OHCI
         * won't work at all.  blacklist them.

diff --git a/drivers/usb/host/ohci.h b/drivers/usb/host/ohci.h
index 382444c8b44cfe6e8c9ce201566ce969968292d7..12742d002d2dc421c61dc25352ff687247b1b3cf 100644 (file)
--- a/drivers/usb/host/ohci.h
+++ b/drivers/usb/host/ohci.h
@@ -418,6 +418,7 @@ struct ohci_hcd {
 #define        OHCI_QUIRK_AMD_PLL      0x200                   /* AMD PLL quirk*/
 #define        OHCI_QUIRK_AMD_PREFETCH 0x400                   /* pre-fetch for ISO transfer */
 #define        OHCI_QUIRK_GLOBAL_SUSPEND       0x800           /* must suspend ports */
+#define        OHCI_QUIRK_QEMU         0x1000                  /* relax timing expectations */
 
        // there are also chip quirks/bugs in init logic