diff options
Diffstat (limited to 'drivers/usb/core/urb.c')
| -rw-r--r-- | drivers/usb/core/urb.c | 12 |
1 files changed, 12 insertions, 0 deletions
diff --git a/drivers/usb/core/urb.c b/drivers/usb/core/urb.c index 3376055f36e..0885d4abdc6 100644 --- a/drivers/usb/core/urb.c +++ b/drivers/usb/core/urb.c @@ -241,6 +241,12 @@ EXPORT_SYMBOL_GPL(usb_unanchor_urb); * If the USB subsystem can't allocate sufficient bandwidth to perform * the periodic request, submitting such a periodic request should fail. * + * For devices under xHCI, the bandwidth is reserved at configuration time, or + * when the alt setting is selected. If there is not enough bus bandwidth, the + * configuration/alt setting request will fail. Therefore, submissions to + * periodic endpoints on devices under xHCI should never fail due to bandwidth + * constraints. + * * Device drivers must explicitly request that repetition, by ensuring that * some URB is always on the endpoint's queue (except possibly for short * periods during completion callacks). When there is no longer an urb @@ -351,6 +357,7 @@ int usb_submit_urb(struct urb *urb, gfp_t mem_flags) if (xfertype == USB_ENDPOINT_XFER_ISOC) { int n, len; + /* FIXME SuperSpeed isoc endpoints have up to 16 bursts */ /* "high bandwidth" mode, 1-3 packets/uframe? */ if (dev->speed == USB_SPEED_HIGH) { int mult = 1 + ((max >> 11) & 0x03); @@ -426,6 +433,11 @@ int usb_submit_urb(struct urb *urb, gfp_t mem_flags) return -EINVAL; /* too big? */ switch (dev->speed) { + case USB_SPEED_SUPER: /* units are 125us */ + /* Handle up to 2^(16-1) microframes */ + if (urb->interval > (1 << 15)) + return -EINVAL; + max = 1 << 15; case USB_SPEED_HIGH: /* units are microframes */ /* NOTE usb handles 2^15 */ if (urb->interval > (1024 * 8)) |