Skip to content

Commit

Permalink
USB: EHCI: No SSPLIT allowed in uframe 7
Browse files Browse the repository at this point in the history
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>
  • Loading branch information
Alan Stern authored and Greg Kroah-Hartman committed Oct 11, 2013
1 parent 2b90f01 commit 8c05dc5
Showing 1 changed file with 4 additions and 0 deletions.
4 changes: 4 additions & 0 deletions drivers/usb/host/ehci-sched.c
Original file line number Diff line number Diff line change
Expand Up @@ -1286,6 +1286,10 @@ sitd_slot_ok (

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;
Expand Down

0 comments on commit 8c05dc5

Please sign in to comment.