Intel xhci: Ignore spurious successful event.
The xHCI host controller in the Panther Point chipset sometimes produces
spurious events on the event ring. If it receives a short packet, it
first puts a Transfer Event with a short transfer completion code on the
event ring. Then it puts a Transfer Event with a successful completion
code on the ring for the same TD. The xHCI driver correctly processes the
short transfer completion code, gives the URB back to the driver, and then
prints a warning in dmesg about the spurious event. These warning
messages really fill up dmesg when an HD webcam is plugged into xHCI.
This spurious successful event behavior isn't technically disallowed by
the xHCI specification, so make the xHCI driver just ignore the spurious
completion event.
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
diff --git a/drivers/usb/host/xhci-pci.c b/drivers/usb/host/xhci-pci.c
index faf039a..eafd17f 100644
--- a/drivers/usb/host/xhci-pci.c
+++ b/drivers/usb/host/xhci-pci.c
@@ -118,6 +118,10 @@
/* AMD PLL quirk */
if (pdev->vendor == PCI_VENDOR_ID_AMD && usb_amd_find_chipset_info())
xhci->quirks |= XHCI_AMD_PLL_FIX;
+ if (pdev->vendor == PCI_VENDOR_ID_INTEL &&
+ pdev->device == PCI_DEVICE_ID_INTEL_PANTHERPOINT_XHCI) {
+ xhci->quirks |= XHCI_SPURIOUS_SUCCESS;
+ }
/* Make sure the HC is halted. */
retval = xhci_halt(xhci);
diff --git a/drivers/usb/host/xhci-ring.c b/drivers/usb/host/xhci-ring.c
index d1498c0..56f6c58 100644
--- a/drivers/usb/host/xhci-ring.c
+++ b/drivers/usb/host/xhci-ring.c
@@ -2061,6 +2061,16 @@
if (!event_seg) {
if (!ep->skip ||
!usb_endpoint_xfer_isoc(&td->urb->ep->desc)) {
+ /* Some host controllers give a spurious
+ * successful event after a short transfer.
+ * Ignore it.
+ */
+ if ((xhci->quirks & XHCI_SPURIOUS_SUCCESS) &&
+ ep_ring->last_td_was_short) {
+ ep_ring->last_td_was_short = false;
+ ret = 0;
+ goto cleanup;
+ }
/* HC is busted, give up! */
xhci_err(xhci,
"ERROR Transfer event TRB DMA ptr not "
@@ -2071,6 +2081,10 @@
ret = skip_isoc_td(xhci, td, event, ep, &status);
goto cleanup;
}
+ if (trb_comp_code == COMP_SHORT_TX)
+ ep_ring->last_td_was_short = true;
+ else
+ ep_ring->last_td_was_short = false;
if (ep->skip) {
xhci_dbg(xhci, "Found td. Clear skip flag.\n");
diff --git a/drivers/usb/host/xhci.h b/drivers/usb/host/xhci.h
index 0772a8c..5cfeb86 100644
--- a/drivers/usb/host/xhci.h
+++ b/drivers/usb/host/xhci.h
@@ -1123,6 +1123,7 @@
*/
u32 cycle_state;
unsigned int stream_id;
+ bool last_td_was_short;
};
struct xhci_erst_entry {
@@ -1290,6 +1291,7 @@
#define XHCI_RESET_EP_QUIRK (1 << 1)
#define XHCI_NEC_HOST (1 << 2)
#define XHCI_AMD_PLL_FIX (1 << 3)
+#define XHCI_SPURIOUS_SUCCESS (1 << 4)
/* There are two roothubs to keep track of bus suspend info for */
struct xhci_bus_state bus_state[2];
/* Is each xHCI roothub port a USB 3.0, USB 2.0, or USB 1.1 port? */