USB: EHCI: No SSPLIT allowed in uframe 7
The scheduling code in ehci-hcd contains an error. For full-speed
isochronous-OUT transfers, the EHCI spec forbids scheduling
Start-Split transactions in H-microframe 7, but the driver allows it
anyway. This patch adds a check to prevent it.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/drivers/usb/host/ehci-sched.c b/drivers/usb/host/ehci-sched.c
index 4b0903c..1fc2bef 100644
--- a/drivers/usb/host/ehci-sched.c
+++ b/drivers/usb/host/ehci-sched.c
@@ -1286,6 +1286,10 @@
mask = stream->raw_mask << (uframe & 7);
+ /* for OUT, don't wrap SSPLIT into H-microframe 7 */
+ if (((stream->raw_mask & 0xff) << (uframe & 7)) >= (1 << 7))
+ return 0;
+
/* for IN, don't wrap CSPLIT into the next frame */
if (mask & ~0xffff)
return 0;