From patchwork Tue Jul 10 14:04:42 2012 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Lauri Hintsala X-Patchwork-Id: 1177681 Return-Path: X-Original-To: patchwork-linux-mmc@patchwork.kernel.org Delivered-To: patchwork-process-083081@patchwork2.kernel.org Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by patchwork2.kernel.org (Postfix) with ESMTP id 33717DFF34 for ; Tue, 10 Jul 2012 14:15:11 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752450Ab2GJOPK (ORCPT ); Tue, 10 Jul 2012 10:15:10 -0400 Received: from bluegiga.fi ([194.100.31.45]:59895 "EHLO darkblue.bluegiga.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752364Ab2GJOPJ (ORCPT ); Tue, 10 Jul 2012 10:15:09 -0400 X-Greylist: delayed 624 seconds by postgrey-1.27 at vger.kernel.org; Tue, 10 Jul 2012 10:15:08 EDT Received: from [10.1.1.28] ([10.1.1.28]) by darkblue.bluegiga.com with Microsoft SMTPSVC(6.0.3790.4675); Tue, 10 Jul 2012 17:04:42 +0300 Message-ID: <4FFC367A.8020100@bluegiga.com> Date: Tue, 10 Jul 2012 17:04:42 +0300 From: Lauri Hintsala User-Agent: Mozilla/5.0 (X11; Linux i686; rv:13.0) Gecko/20120615 Thunderbird/13.0.1 MIME-Version: 1.0 To: Shawn Guo , Wolfram Sang , Koen Beel , Marek Vasut CC: linux-mmc@vger.kernel.org, "linux-arm-kernel@lists.infradead.org" , Veli-Pekka Peltola Subject: mmc: mxs: DEADLOCK X-OriginalArrivalTime: 10 Jul 2012 14:04:42.0657 (UTC) FILETIME=[F4197910:01CD5EA4] Sender: linux-mmc-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-mmc@vger.kernel.org Hi, I was able to get deadlock with CONFIG_DEBUG_SPINLOCK enabled. I added also CONFIG_PROVE_LOCKING to get more verbose output. I got following error message after SDIO device has been powered. I'm able to replicate issue with Linux next-20120710. Platform is imx28. [ 79.660000] ============================================= [ 79.660000] [ INFO: possible recursive locking detected ] [ 79.660000] 3.4.0-00009-g3e96082-dirty #11 Not tainted [ 79.660000] --------------------------------------------- [ 79.660000] swapper/0 is trying to acquire lock: [ 79.660000] (&(&host->lock)->rlock#2){-.....}, at: [] mxs_mmc_enable_sdio_irq+0x18/0xd4 [ 79.660000] [ 79.660000] but task is already holding lock: [ 79.660000] (&(&host->lock)->rlock#2){-.....}, at: [] mxs_mmc_irq_handler+0x1c/0xe8 [ 79.660000] [ 79.660000] other info that might help us debug this: [ 79.660000] Possible unsafe locking scenario: [ 79.660000] [ 79.660000] CPU0 [ 79.660000] ---- [ 79.660000] lock(&(&host->lock)->rlock#2); [ 79.660000] lock(&(&host->lock)->rlock#2); [ 79.660000] [ 79.660000] *** DEADLOCK *** [ 79.660000] [ 79.660000] May be due to missing lock nesting notation [ 79.660000] [ 79.660000] 1 lock held by swapper/0: [ 79.660000] #0: (&(&host->lock)->rlock#2){-.....}, at: [] mxs_mmc_irq_handler+0x1c/0xe8 [ 79.660000] [ 79.660000] stack backtrace: [ 79.660000] [] (unwind_backtrace+0x0/0xf4) from [] (__lock_acquire+0x1948/0x1d48) [ 79.660000] [] (__lock_acquire+0x1948/0x1d48) from [] (lock_acquire+0xe0/0xf8) [ 79.660000] [] (lock_acquire+0xe0/0xf8) from [] (_raw_spin_lock_irqsave+0x44/0x58) [ 79.660000] [] (_raw_spin_lock_irqsave+0x44/0x58) from [] (mxs_mmc_enable_sdio_irq+0x18/0xd4) [ 79.660000] [] (mxs_mmc_enable_sdio_irq+0x18/0xd4) from [] (mxs_mmc_irq_handler+0xd4/0xe8) [ 79.660000] [] (mxs_mmc_irq_handler+0xd4/0xe8) from [] (handle_irq_event_percpu+0x70/0x254) [ 79.660000] [] (handle_irq_event_percpu+0x70/0x254) from [] (handle_irq_event+0x3c/0x5c) [ 79.660000] [] (handle_irq_event+0x3c/0x5c) from [] (handle_level_irq+0x90/0x110) [ 79.660000] [] (handle_level_irq+0x90/0x110) from [] (generic_handle_irq+0x38/0x50) [ 79.660000] [] (generic_handle_irq+0x38/0x50) from [] (handle_IRQ+0x30/0x84) [ 79.660000] [] (handle_IRQ+0x30/0x84) from [] (__irq_svc+0x38/0x60) [ 79.660000] [] (__irq_svc+0x38/0x60) from [] (default_idle+0x2c/0x40) [ 79.660000] [] (default_idle+0x2c/0x40) from [] (cpu_idle+0x64/0xcc) [ 79.660000] [] (cpu_idle+0x64/0xcc) from [] (start_kernel+0x244/0x2c8) [ 79.660000] BUG: spinlock lockup on CPU#0, swapper/0 [ 79.660000] lock: c398cb2c, .magic: dead4ead, .owner: swapper/0, .owner_cpu: 0 [ 79.660000] [] (unwind_backtrace+0x0/0xf4) from [] (do_raw_spin_lock+0xf0/0x144) [ 79.660000] [] (do_raw_spin_lock+0xf0/0x144) from [] (_raw_spin_lock_irqsave+0x4c/0x58) [ 79.660000] [] (_raw_spin_lock_irqsave+0x4c/0x58) from [] (mxs_mmc_enable_sdio_irq+0x18/0xd4) [ 79.660000] [] (mxs_mmc_enable_sdio_irq+0x18/0xd4) from [] (mxs_mmc_irq_handler+0xd4/0xe8) [ 79.660000] [] (mxs_mmc_irq_handler+0xd4/0xe8) from [] (handle_irq_event_percpu+0x70/0x254) [ 79.660000] [] (handle_irq_event_percpu+0x70/0x254) from [] (handle_irq_event+0x3c/0x5c) [ 79.660000] [] (handle_irq_event+0x3c/0x5c) from [] (handle_level_irq+0x90/0x110) [ 79.660000] [] (handle_level_irq+0x90/0x110) from [] (generic_handle_irq+0x38/0x50) [ 79.660000] [] (generic_handle_irq+0x38/0x50) from [] (handle_IRQ+0x30/0x84) [ 79.660000] [] (handle_IRQ+0x30/0x84) from [] (__irq_svc+0x38/0x60) [ 79.660000] [] (__irq_svc+0x38/0x60) from [] (default_idle+0x2c/0x40) [ 79.660000] [] (default_idle+0x2c/0x40) from [] (cpu_idle+0x64/0xcc) [ 79.660000] [] (cpu_idle+0x64/0xcc) from [] (start_kernel+0x244/0x2c8) I found a way to fix this issue: else if (stat & BM_SSP_CTRL1_RESP_ERR_IRQ) Is there any reason to keep mmc_signal_sdio_irq inside the spinlock? mmc_signal_sdio_irq calls mxs_mmc_enable_sdio_irq and it tries to acquire lock while it is already acquired. Best regards, Lauri Hintsala Acked-by: Shawn Guo --- To unsubscribe from this list: send the line "unsubscribe linux-mmc" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html --- a/drivers/mmc/host/mxs-mmc.c +++ b/drivers/mmc/host/mxs-mmc.c @@ -278,11 +278,11 @@ static irqreturn_t mxs_mmc_irq_handler(int irq, void *dev_id) writel(stat & MXS_MMC_IRQ_BITS, host->base + HW_SSP_CTRL1(host) + STMP_OFFSET_REG_CLR); + spin_unlock(&host->lock); + if ((stat & BM_SSP_CTRL1_SDIO_IRQ) && (stat & BM_SSP_CTRL1_SDIO_IRQ_EN)) mmc_signal_sdio_irq(host->mmc); - spin_unlock(&host->lock); - if (stat & BM_SSP_CTRL1_RESP_TIMEOUT_IRQ) cmd->error = -ETIMEDOUT;