xhci: Avoid infinite loop when sg urb requires too many trbs

Currently prepare_ring() returns -ENOMEM if the urb won't fit into a
single ring segment.  usb_sg_wait() treats this error as a temporary
condition and will keep retrying until something else goes wrong.

The number of retries should be limited in usb_sg_wait(), but also
prepare_ring() should not return an error code that suggests it might
be worth retrying.  Change it to -EINVAL.

Reported-by: [email protected]
References: http://bugs.debian.org/733907
Fixes: 35773dac5f ('usb: xhci: Link TRB must not occur within a USB payload burst')
Cc: stable <[email protected]> # 3.12
Signed-off-by: Ben Hutchings <[email protected]>
Signed-off-by: Sarah Sharp <[email protected]>
This commit is contained in:
Ben Hutchings 2014-01-06 03:16:32 +00:00 • committed by Sarah Sharp
commit d6c9ea9069

View file

@ -3000,7 +3000,7 @@ static int prepare_ring(struct xhci_hcd *xhci, struct xhci_ring *ep_ring,
if (num_trbs >= TRBS_PER_SEGMENT) {
xhci_err(xhci, "Too many fragments %d, max %d\n",
num_trbs, TRBS_PER_SEGMENT - 1);
return -ENOMEM;
return -EINVAL;
}
nop_cmd = cpu_to_le32(TRB_TYPE(TRB_TR_NOOP) |