From patchwork Thu Jul 11 14:24:03 2013 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Luis Henriques X-Patchwork-Id: 258588 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 B28A82C02CE for ; Fri, 12 Jul 2013 03:21:55 +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 1UxKYn-0007Qd-It; Thu, 11 Jul 2013 17:21:41 +0000 Received: from youngberry.canonical.com ([91.189.89.112]) by huckleberry.canonical.com with esmtp (Exim 4.76) (envelope-from ) id 1UxHok-0007hS-Vu for kernel-team@lists.ubuntu.com; Thu, 11 Jul 2013 14:25:59 +0000 Received: from bl15-104-132.dsl.telepac.pt ([188.80.104.132] helo=localhost) by youngberry.canonical.com with esmtpsa (TLS1.0:DHE_RSA_AES_128_CBC_SHA1:16) (Exim 4.71) (envelope-from ) id 1UxHoj-0001by-SU; Thu, 11 Jul 2013 14:25:58 +0000 From: Luis Henriques To: linux-kernel@vger.kernel.org, stable@vger.kernel.org, kernel-team@lists.ubuntu.com Subject: [PATCH 33/98] drivers/dma/pl330.c: fix locking in pl330_free_chan_resources() Date: Thu, 11 Jul 2013 15:24:03 +0100 Message-Id: <1373552708-15235-34-git-send-email-luis.henriques@canonical.com> X-Mailer: git-send-email 1.8.1.2 In-Reply-To: <1373552708-15235-1-git-send-email-luis.henriques@canonical.com> References: <1373552708-15235-1-git-send-email-luis.henriques@canonical.com> X-Extended-Stable: 3.5 X-Mailman-Approved-At: Thu, 11 Jul 2013 17:21:41 +0000 Cc: Vinod Koul , Bartlomiej Zolnierkiewicz , Tomasz Figa , Kyungmin Park , Andrew Morton , Linus Torvalds 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 3.5.7.17 -stable review patch. If anyone has any objections, please let me know. ------------------ From: Bartlomiej Zolnierkiewicz commit da331ba8e9c5de72a27e50f71105395bba6eebe0 upstream. tasklet_kill() may sleep so call it before taking pch->lock. Fixes following lockup: BUG: scheduling while atomic: cat/2383/0x00000002 Modules linked in: unwind_backtrace+0x0/0xfc __schedule_bug+0x4c/0x58 __schedule+0x690/0x6e0 sys_sched_yield+0x70/0x78 tasklet_kill+0x34/0x8c pl330_free_chan_resources+0x24/0x88 dma_chan_put+0x4c/0x50 [...] BUG: spinlock lockup suspected on CPU#0, swapper/0/0 lock: 0xe52aa04c, .magic: dead4ead, .owner: cat/2383, .owner_cpu: 1 unwind_backtrace+0x0/0xfc do_raw_spin_lock+0x194/0x204 _raw_spin_lock_irqsave+0x20/0x28 pl330_tasklet+0x2c/0x5a8 tasklet_action+0xfc/0x114 __do_softirq+0xe4/0x19c irq_exit+0x98/0x9c handle_IPI+0x124/0x16c gic_handle_irq+0x64/0x68 __irq_svc+0x40/0x70 cpuidle_wrap_enter+0x4c/0xa0 cpuidle_enter_state+0x18/0x68 cpuidle_idle_call+0xac/0xe0 cpu_idle+0xac/0xf0 Signed-off-by: Bartlomiej Zolnierkiewicz Signed-off-by: Kyungmin Park Acked-by: Jassi Brar Cc: Vinod Koul Cc: Tomasz Figa Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Luis Henriques --- drivers/dma/pl330.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/dma/pl330.c b/drivers/dma/pl330.c index f5843bc..de4ec1a 100644 --- a/drivers/dma/pl330.c +++ b/drivers/dma/pl330.c @@ -2462,10 +2462,10 @@ static void pl330_free_chan_resources(struct dma_chan *chan) struct dma_pl330_chan *pch = to_pchan(chan); unsigned long flags; - spin_lock_irqsave(&pch->lock, flags); - tasklet_kill(&pch->task); + spin_lock_irqsave(&pch->lock, flags); + pl330_release_channel(pch->pl330_chid); pch->pl330_chid = NULL;