Under OHCI, UHCI, and EHCI, if an alternate interface setting took too
much of the bus bandwidth, then submit_urb() would fail. The xHCI host
controller does bandwidth checking when the alternate interface setting is
installed, so usb_set_interface() can fail. If it does, try the next
alternate interface setting.
Signed-off-by: Sarah Sharp <sarah.a.sharp@xxxxxxxxxxxxxxx>
Tested-by: Andiry Xu <andiry.xu@xxxxxxx>
---
drivers/media/video/gspca/gspca.c | 10 ++++++----
1 files changed, 6 insertions(+), 4 deletions(-)
diff --git a/drivers/media/video/gspca/gspca.c b/drivers/media/video/gspca/gspca.c
index 222af47..6de3117 100644
--- a/drivers/media/video/gspca/gspca.c
+++ b/drivers/media/video/gspca/gspca.c
@@ -643,6 +643,7 @@ static struct usb_host_endpoint *get_ep(struct gspca_dev *gspca_dev)
xfer = gspca_dev->cam.bulk ? USB_ENDPOINT_XFER_BULK
: USB_ENDPOINT_XFER_ISOC;
i = gspca_dev->alt; /* previous alt setting */
+find_alt:
if (gspca_dev->cam.reverse_alts) {
while (++i < gspca_dev->nbalt) {
ep = alt_xfer(&intf->altsetting[i], xfer);
@@ -666,10 +667,11 @@ static struct usb_host_endpoint *get_ep(struct gspca_dev *gspca_dev)
if (gspca_dev->nbalt > 1) {
gspca_input_destroy_urb(gspca_dev);
ret = usb_set_interface(gspca_dev->dev, gspca_dev->iface, i);
- if (ret < 0) {
- err("set alt %d err %d", i, ret);
- ep = NULL;
- }
+ /* xHCI hosts will reject set interface requests
+ * if they take too much bandwidth, so try again.
+ */
+ if (ret < 0)
+ goto find_alt;
gspca_input_create_urb(gspca_dev);
}
return ep;
--
1.6.3.3
--
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