From: Hans de Goede <hdegoede@xxxxxxxxxx>
I encountered a result of COMP_2ND_BW_ERR while improving how the pwc
webcam driver handles not having the full usb1 bandwidth available to
itself.
I created the following test setup, a NEC xhci controller with a
single TT USB 2 hub plugged into it, with a usb keyboard and a pwc webcam
plugged into the usb2 hub. This caused the following to show up in dmesg
when trying to stream from the pwc camera at its highest alt setting:
xhci_hcd 0000:01:00.0: ERROR: unexpected command completion code 0x23.
usb 6-2.1: Not enough bandwidth for altsetting 9
And usb_set_interface returned -EINVAL, which caused my pwc code to not
do the right thing as it expected -ENOSPC.
This patch makes the xhci driver properly handle COMP_2ND_BW_ERR and makes
usb_set_interface return -ENOSPC as expected.
This should be backported to stable kernels as old as 2.6.32.
Signed-off-by: Hans de Goede <hdegoede@xxxxxxxxxx>
Signed-off-by: Sarah Sharp <sarah.a.sharp@xxxxxxxxxxxxxxx>
Cc: stable@xxxxxxxxxxxxxxx
---
drivers/usb/host/xhci.c | 1 +
drivers/usb/host/xhci.h | 1 -
2 files changed, 1 insertions(+), 1 deletions(-)
diff --git a/drivers/usb/host/xhci.c b/drivers/usb/host/xhci.c
index f3d0b8d..6693de7 100644
--- a/drivers/usb/host/xhci.c
+++ b/drivers/usb/host/xhci.c
@@ -1623,6 +1623,7 @@ static int xhci_configure_endpoint_result(struct xhci_hcd *xhci,
/* FIXME: can we allocate more resources for the HC? */
break;
case COMP_BW_ERR:
+ case COMP_2ND_BW_ERR:
dev_warn(&udev->dev, "Not enough bandwidth "
"for new device state.\n");
ret = -ENOSPC;
diff --git a/drivers/usb/host/xhci.h b/drivers/usb/host/xhci.h
index ecd2ad5..fb99c83 100644
--- a/drivers/usb/host/xhci.h
+++ b/drivers/usb/host/xhci.h
@@ -1033,7 +1033,6 @@ struct xhci_transfer_event {
/* Invalid Stream ID Error */
#define COMP_STRID_ERR 34
/* Secondary Bandwidth Error - may be returned by a Configure Endpoint cmd */
-/* FIXME - check for this */
#define COMP_2ND_BW_ERR 35
/* Split Transaction Error */
#define COMP_SPLIT_ERR 36
--
1.7.5.4
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