From mboxrd@z Thu Jan 1 00:00:00 1970 From: Sebastian Capella Subject: Re: [PATCH RFC v1 1/3] ARM: Add irq disabled version of soft_restart. Date: Mon, 24 Feb 2014 16:22:37 -0800 Message-ID: <20140225002237.10580.89781@capellas-linux> References: <1392774729-3235-1-git-send-email-sebastian.capella@linaro.org> <1392774729-3235-2-git-send-email-sebastian.capella@linaro.org> <20140222102616.GG21483@n2100.arm.linux.org.uk> <20140224231345.10580.62916@capellas-linux> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20140224231345.10580.62916@capellas-linux> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=m.gmane.org@lists.infradead.org To: Sebastian Capella , Russell King - ARM Linux Cc: linaro-kernel@lists.linaro.org, linux-pm@vger.kernel.org, Will Deacon , linux-kernel@vger.kernel.org, Russ Dill , Robin Holt , Andrew Morton , Thomas Gleixner , linux-arm-kernel@lists.infradead.org List-Id: linux-pm@vger.kernel.org Quoting Sebastian Capella (2014-02-24 15:13:45) > Quoting Russell King - ARM Linux (2014-02-22 02:26:17) > > On Tue, Feb 18, 2014 at 05:52:07PM -0800, Sebastian Capella wrote: > > > From: Russ Dill > > > > > > This adds the ability to run soft_restart with local_irq/fiq_disable > > > already called. This is helpful for the hibernation code paths. > > > > I'd rather keep this simple. There's no problem with calling soft_restart > > with interrupts already disabled. local_irq_disable()/local_fiq_disable() > > there should be harmless. > > Hi Russell, > > I'm observing a data abort loop when I replace this call: > > In the local_irq_disable, it ends up calling trace_hardirqs_off > (CONFIG_TRACE_IRQFLAGS_SUPPORT is enabled), which calls > trace_hardirqs_off_caller which checks lockdep_recursion in the > current task, but we've switched to a temporary stack with the > call_with_stack, and get_current is returning NULL. This > triggers a data abort, which calls trace_hardirqs_off > again and so on. > > Do you have any suggestions here? I'll go ahead and send v2, leaving the soft_restart_noirq in place for now since it's already past midnight in Surrey. Thanks! Sebastian From mboxrd@z Thu Jan 1 00:00:00 1970 From: sebastian.capella@linaro.org (Sebastian Capella) Date: Mon, 24 Feb 2014 16:22:37 -0800 Subject: [PATCH RFC v1 1/3] ARM: Add irq disabled version of soft_restart. In-Reply-To: <20140224231345.10580.62916@capellas-linux> References: <1392774729-3235-1-git-send-email-sebastian.capella@linaro.org> <1392774729-3235-2-git-send-email-sebastian.capella@linaro.org> <20140222102616.GG21483@n2100.arm.linux.org.uk> <20140224231345.10580.62916@capellas-linux> Message-ID: <20140225002237.10580.89781@capellas-linux> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org Quoting Sebastian Capella (2014-02-24 15:13:45) > Quoting Russell King - ARM Linux (2014-02-22 02:26:17) > > On Tue, Feb 18, 2014 at 05:52:07PM -0800, Sebastian Capella wrote: > > > From: Russ Dill > > > > > > This adds the ability to run soft_restart with local_irq/fiq_disable > > > already called. This is helpful for the hibernation code paths. > > > > I'd rather keep this simple. There's no problem with calling soft_restart > > with interrupts already disabled. local_irq_disable()/local_fiq_disable() > > there should be harmless. > > Hi Russell, > > I'm observing a data abort loop when I replace this call: > > In the local_irq_disable, it ends up calling trace_hardirqs_off > (CONFIG_TRACE_IRQFLAGS_SUPPORT is enabled), which calls > trace_hardirqs_off_caller which checks lockdep_recursion in the > current task, but we've switched to a temporary stack with the > call_with_stack, and get_current is returning NULL. This > triggers a data abort, which calls trace_hardirqs_off > again and so on. > > Do you have any suggestions here? I'll go ahead and send v2, leaving the soft_restart_noirq in place for now since it's already past midnight in Surrey. Thanks! Sebastian