From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756450AbaGXJfI (ORCPT ); Thu, 24 Jul 2014 05:35:08 -0400 Received: from mail-we0-f180.google.com ([74.125.82.180]:62155 "EHLO mail-we0-f180.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753005AbaGXJfF (ORCPT ); Thu, 24 Jul 2014 05:35:05 -0400 Message-ID: <53D0D348.406@linaro.org> Date: Thu, 24 Jul 2014 11:35:04 +0200 From: Daniel Lezcano User-Agent: Mozilla/5.0 (X11; Linux i686; rv:24.0) Gecko/20100101 Thunderbird/24.5.0 MIME-Version: 1.0 To: Krzysztof Kozlowski , "Rafael J. Wysocki" , linux-pm@vger.kernel.org, linux-kernel@vger.kernel.org CC: Colin Cross , Kyungmin Park , Marek Szyprowski , Bartlomiej Zolnierkiewicz , stable@vger.kernel.org Subject: Re: [PATCH] cpuidle: coupled: Enable interrupts when early returning on invalid driver References: <1406193999-20300-1-git-send-email-k.kozlowski@samsung.com> In-Reply-To: <1406193999-20300-1-git-send-email-k.kozlowski@samsung.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 07/24/2014 11:26 AM, Krzysztof Kozlowski wrote: > cpuidle_enter_state is expected to return with interrupts enabled. > However cpuidle_enter_state_coupled returned with interrupts disabled if > the cpuidle driver was registered without mask of coupled cpus. Hi Krzysztof, may be your patch is right but I would like to clarify one thing. This is the cpuidle driver for exynos. AFAICT, the coupled states shouldn't be enabled for this driver, so how did you face this issue ? > This could be observed as a warning: > [ 1.613132] ------------[ cut here ]------------ > [ 1.613244] WARNING: CPU: 0 PID: 0 at kernel/sched/idle.c:175 cpu_idle_loop+0x2dc/0x6d0() > [ 1.620268] Modules linked in: > [ 1.623311] CPU: 0 PID: 0 Comm: swapper/0 Not tainted 3.16.0-rc4-00102-g7669ccdbf8af-dirty #81 > [ 1.623619] dwmmc_exynos 12510000.mshc: 1 slots initialized > [ 1.624890] logger: created 256K log 'log_main' > [ 1.625483] logger: created 256K log 'log_events' > [ 1.626084] logger: created 256K log 'log_radio' > [ 1.626699] logger: created 256K log 'log_system' > [ 1.655960] [] (unwind_backtrace) from [] (show_stack+0x10/0x14) > [ 1.663679] [] (show_stack) from [] (dump_stack+0x70/0xbc) > [ 1.670883] [] (dump_stack) from [] (warn_slowpath_common+0x68/0x8c) > [ 1.678954] [] (warn_slowpath_common) from [] (warn_slowpath_null+0x1c/0x24) > [ 1.687720] [] (warn_slowpath_null) from [] (cpu_idle_loop+0x2dc/0x6d0) > [ 1.696052] [] (cpu_idle_loop) from [] (cpupri_find+0x0/0xd4) > [ 1.703518] [] (cpupri_find) from [] (processor_id+0x0/0x2c) > [ 1.710917] ---[ end trace a85327313857296e ]--- > > Enable the interrupts also when early returning from > cpuidle_enter_state_coupled due to invalid coupled configuration. > > Signed-off-by: Krzysztof Kozlowski > Fixes: 4126c0197bc8 ("cpuidle: add support for states that affect multiple cpus") > Cc: > --- > drivers/cpuidle/coupled.c | 4 +++- > 1 file changed, 3 insertions(+), 1 deletion(-) > > diff --git a/drivers/cpuidle/coupled.c b/drivers/cpuidle/coupled.c > index 73fe2f8d7f96..2b57c267e855 100644 > --- a/drivers/cpuidle/coupled.c > +++ b/drivers/cpuidle/coupled.c > @@ -463,8 +463,10 @@ int cpuidle_enter_state_coupled(struct cpuidle_device *dev, > struct cpuidle_coupled *coupled = dev->coupled; > int w; > > - if (!coupled) > + if (!coupled) { > + local_irq_enable(); > return -EINVAL; > + } > > while (coupled->prevent) { > cpuidle_coupled_clear_pokes(dev->cpu); > -- Linaro.org │ Open source software for ARM SoCs Follow Linaro: Facebook | Twitter | Blog