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: jidanni@jidanni.org
References: http://bugs.debian.org/733907
Fixes: 35773dac5f86 ('usb: xhci: Link TRB must not occur within a USB payload burst')
Cc: stable <stable@vger.kernel.org> # 3.12
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
diff --git a/drivers/usb/host/xhci-ring.c b/drivers/usb/host/xhci-ring.c
index 09b2b55..a0b248c 100644
--- a/drivers/usb/host/xhci-ring.c
+++ b/drivers/usb/host/xhci-ring.c
@@ -3000,7 +3000,7 @@
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) |
