From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754366AbbAHKI1 (ORCPT ); Thu, 8 Jan 2015 05:08:27 -0500 Received: from cnbjrel02.sonyericsson.com ([219.141.167.166]:5323 "EHLO cnbjrel02.sonyericsson.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752756AbbAHKIZ convert rfc822-to-8bit (ORCPT ); Thu, 8 Jan 2015 05:08:25 -0500 From: "Wang, Yalin" To: "'chris@printf.net'" , "'ulf.hansson@linaro.org'" , "'tim.kryger@gmail.com'" , "'tgih.jun@samsung.com'" , "'johan.rudholm@axis.com'" , "'linux-mmc@vger.kernel.org'" , "'linux-kernel@vger.kernel.org'" , "'linux-arm-kernel@lists.infradead.org'" Date: Thu, 8 Jan 2015 18:08:21 +0800 Subject: [RFC V2] mmc:change mmc_init workqueue into a freezable workqueue Thread-Topic: [RFC V2] mmc:change mmc_init workqueue into a freezable workqueue Thread-Index: AdArKscTl4nihDsKS+OgMy1GnhD4twAACQSw Message-ID: <35FD53F367049845BC99AC72306C23D103EDAF89E193@CNBJMBX05.corpusers.net> References: <35FD53F367049845BC99AC72306C23D103EDAF89E192@CNBJMBX05.corpusers.net> In-Reply-To: <35FD53F367049845BC99AC72306C23D103EDAF89E192@CNBJMBX05.corpusers.net> Accept-Language: en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: acceptlanguage: en-US Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 8BIT MIME-Version: 1.0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org This patch fix the mmc driver suspend/resume conflict problems, mmc workqueue will queue mmc_rescan(), and it will call some pm_runtime_* functions, this will conflict with suspend path sometimes, and will result in some strange behavior: Suspend path: -000 |context_switch(inline) -000 |__schedule() -001 |schedule_preempt_disabled() -002 |spin_lock(inline) -002 |__mutex_lock_common(inline) -002 |__mutex_lock_slowpath(lock_count = 0xEDCD0F48) -003 |__mutex_fastpath_lock(inline) -003 |mutex_lock(lock = 0xEDCD0F48) -004 |sdhci_do_set_ios(host = 0xEDCD0CC0, ios = 0xEDCD0A70) -005 |sdhci_set_ios(?, ios = 0xEDCD0A70) -006 |mmc_set_ios(host = 0xEDCD0800) -007 |mmc_delay(inline) -007 |mmc_power_off(host = 0xEDCD0800) -008 |mmc_suspend_host(inline) -008 |mmc_suspend_host(host = 0xEDCD0800) -009 |mmc_host_suspend(dev = 0xEDCD0808) -010 |dpm_run_callback(cb = 0xC0627A88, dev = 0xEDCD0808, state = (event = 2), info = 0xC0B6EF9B) -011 |__device_suspend(dev = 0xEDCD0808, state = (event = 2), ?) -012 |device_suspend(inline) -012 |dpm_suspend(state = (event = 2)) -013 |suspend_devices_and_enter(state = 3) -014 |enter_state(inline) -014 |pm_suspend(state = 3) -015 |try_to_suspend(?) -016 |static_key_false(inline) -016 |trace_workqueue_execute_end(inline) -016 |process_one_work(worker = 0xD5E87040, work = 0xC0E3FF54) -017 |worker_thread(__worker = 0xD5E87040) -018 |kthread(_create = 0xE9FFBF10) -019 |kernel_thread_exit(asm) --- |end of frame mmc_rescan() resume path: -000 |context_switch(inline) -000 |__schedule() -001 |do_undefinstr(regs = 0xD12242F0) -002 |__und_svc(asm) --> |exception -003 |sdhci_set_power(host = 0xEDCD0CC0, power = 0) -004 |sdhci_do_set_ios(host = 0xEDCD0CC0, ios = 0xEDCD0A70) -005 |sdhci_set_ios(?, ios = 0xEDCD0A70) -006 |mmc_set_ios(host = 0xEDCD0800) -007 |mmc_delay(inline) -007 |mmc_power_up(host = 0xEDCD0800) -008 |mmc_resume_bus(inline) -008 |mmc_resume_bus(host = 0xEDCD0800) -009 |mmc_rpm_hold(host = 0xEDCD0800, ?) -010 |mmc_rescan(work = 0xEDCD0AB0) -011 |static_key_false(inline) -011 |trace_workqueue_execute_end(inline) -011 |process_one_work(worker = 0xE5F0BBC0, work = 0xEDCD0AB0) -012 |worker_thread(__worker = 0xE5F0BBC0) -013 |kthread(_create = 0xD03A5F10) -014 |kernel_thread_exit(asm) --- |end of frame most mmc power callback function don't check this special case, and will cause problems. Signed-off-by: Yalin Wang --- drivers/mmc/core/core.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/mmc/core/core.c b/drivers/mmc/core/core.c index a6c139d..ae8757f 100644 --- a/drivers/mmc/core/core.c +++ b/drivers/mmc/core/core.c @@ -3881,7 +3881,7 @@ static int __init mmc_init(void) { int ret; - workqueue = alloc_ordered_workqueue("kmmcd", 0); + workqueue = alloc_ordered_workqueue("kmmcd", WQ_FREEZABLE); if (!workqueue) return -ENOMEM; -- 2.1.3