From patchwork Fri Jun 7 20:29:23 2013 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kamal Mostafa X-Patchwork-Id: 249831 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from huckleberry.canonical.com (huckleberry.canonical.com [91.189.94.19]) by ozlabs.org (Postfix) with ESMTP id 8353A2C00AA for ; Sat, 8 Jun 2013 06:30:31 +1000 (EST) Received: from localhost ([127.0.0.1] helo=huckleberry.canonical.com) by huckleberry.canonical.com with esmtp (Exim 4.76) (envelope-from ) id 1Ul3Im-0002rT-OT; Fri, 07 Jun 2013 20:30:24 +0000 Received: from youngberry.canonical.com ([91.189.89.112]) by huckleberry.canonical.com with esmtp (Exim 4.76) (envelope-from ) id 1Ul3Hq-0002Oz-7V for kernel-team@lists.ubuntu.com; Fri, 07 Jun 2013 20:29:26 +0000 Received: from c-67-160-231-42.hsd1.ca.comcast.net ([67.160.231.42] helo=fourier) by youngberry.canonical.com with esmtpsa (TLS1.0:DHE_RSA_AES_128_CBC_SHA1:16) (Exim 4.71) (envelope-from ) id 1Ul3Hp-0001cw-Dm; Fri, 07 Jun 2013 20:29:25 +0000 Received: from kamal by fourier with local (Exim 4.80) (envelope-from ) id 1Ul3Hn-0000Q3-5K; Fri, 07 Jun 2013 13:29:23 -0700 From: Kamal Mostafa To: Alan Stern Subject: [ 3.8.y.z extended stable ] Patch "USB: revert periodic scheduling bugfix" has been added to staging queue Date: Fri, 7 Jun 2013 13:29:23 -0700 Message-Id: <1370636963-1581-1-git-send-email-kamal@canonical.com> X-Mailer: git-send-email 1.8.1.2 X-Extended-Stable: 3.8 Cc: Greg Kroah-Hartman , Kamal Mostafa , kernel-team@lists.ubuntu.com, Tim Richardson X-BeenThere: kernel-team@lists.ubuntu.com X-Mailman-Version: 2.1.14 Precedence: list List-Id: Kernel team discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Errors-To: kernel-team-bounces@lists.ubuntu.com Sender: kernel-team-bounces@lists.ubuntu.com This is a note to let you know that I have just added a patch titled USB: revert periodic scheduling bugfix to the linux-3.8.y-queue branch of the 3.8.y.z extended stable tree which can be found at: http://kernel.ubuntu.com/git?p=ubuntu/linux.git;a=shortlog;h=refs/heads/linux-3.8.y-queue This patch is scheduled to be released in version 3.8.13.3. If you, or anyone else, feels it should not be added to this tree, please reply to this email. For more information about the 3.8.y.z tree, see https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable Thanks. -Kamal ------ From 3bbe9a3f1d66b591b7898f819e3bc389b871abbc Mon Sep 17 00:00:00 2001 From: Alan Stern Date: Tue, 28 May 2013 14:03:10 -0400 Subject: USB: revert periodic scheduling bugfix commit fdc03438f53a00294ed9939eb3a1f6db6f3d8963 upstream. This patch reverts commit 3e619d04159be54b3daa0b7036b0ce9e067f4b5d (USB: EHCI: fix bug in scheduling periodic split transfers). The commit was valid -- it fixed a real bug -- but the periodic scheduler in ehci-hcd is in such bad shape (especially the part that handles split transactions) that fixing one bug is very likely to cause another to surface. That's what happened in this case; the result was choppy and noisy playback on certain 24-bit audio devices. The only real fix will be to rewrite this entire section of code. My next project... This fixes https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1136110. Thanks to Tim Richardson for extra testing and feedback, and to Joseph Salisbury and Tyson Tan for tracking down the original source of the problem. Signed-off-by: Alan Stern CC: Joseph Salisbury CC: Tim Richardson Signed-off-by: Greg Kroah-Hartman Signed-off-by: Kamal Mostafa --- drivers/usb/host/ehci-sched.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) -- 1.8.1.2 diff --git a/drivers/usb/host/ehci-sched.c b/drivers/usb/host/ehci-sched.c index 010f686..5a00ef3 100644 --- a/drivers/usb/host/ehci-sched.c +++ b/drivers/usb/host/ehci-sched.c @@ -213,7 +213,7 @@ static inline unsigned char tt_start_uframe(struct ehci_hcd *ehci, __hc32 mask) } static const unsigned char -max_tt_usecs[] = { 125, 125, 125, 125, 125, 125, 125, 25 }; +max_tt_usecs[] = { 125, 125, 125, 125, 125, 125, 30, 0 }; /* carryover low/fullspeed bandwidth that crosses uframe boundries */ static inline void carryover_tt_bandwidth(unsigned short tt_usecs[8])