From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Alan Stern Subject: [ 34/57] USB: UHCI: accept very late isochronous URBs Date: Wed, 2 Oct 2013 21:09:00 -0700 Message-Id: <20131003040638.935871481@linuxfoundation.org> In-Reply-To: <20131003040636.600441214@linuxfoundation.org> References: <20131003040636.600441214@linuxfoundation.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: 3.11-stable review patch. If anyone has any objections, please let me know. ------------------ From: Alan Stern commit bef073b067a7b1874a6b381e0035bb0516d71a77 upstream. Commit 24f531371de1 (USB: EHCI: accept very late isochronous URBs) changed the isochronous API provided by ehci-hcd. URBs submitted too late, so that the time slots for all their packets have already expired, are no longer rejected outright. Instead the submission is accepted, and the URB completes normally with a -EXDEV error for each packet. This is what client drivers expect. This patch implements the same policy in uhci-hcd. It should be applied to all kernels containing commit c44b225077bb (UHCI: implement new semantics for URB_ISO_ASAP). Signed-off-by: Alan Stern Signed-off-by: Greg Kroah-Hartman --- drivers/usb/host/uhci-q.c | 12 ++++++++---- 1 file changed, 8 insertions(+), 4 deletions(-) --- a/drivers/usb/host/uhci-q.c +++ b/drivers/usb/host/uhci-q.c @@ -1303,7 +1303,7 @@ static int uhci_submit_isochronous(struc } /* Fell behind? */ - if (uhci_frame_before_eq(frame, next)) { + if (!uhci_frame_before_eq(next, frame)) { /* USB_ISO_ASAP: Round up to the first available slot */ if (urb->transfer_flags & URB_ISO_ASAP) @@ -1311,13 +1311,17 @@ static int uhci_submit_isochronous(struc -qh->period; /* - * Not ASAP: Use the next slot in the stream. If - * the entire URB falls before the threshold, fail. + * Not ASAP: Use the next slot in the stream, + * no matter what. */ else if (!uhci_frame_before_eq(next, frame + (urb->number_of_packets - 1) * qh->period)) - return -EXDEV; + dev_dbg(uhci_dev(uhci), "iso underrun %p (%u+%u < %u)\n", + urb, frame, + (urb->number_of_packets - 1) * + qh->period, + next); } }