Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753847Ab1CKTCT (ORCPT ); Fri, 11 Mar 2011 14:02:19 -0500 Received: from wolverine02.qualcomm.com ([199.106.114.251]:45952 "EHLO wolverine02.qualcomm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753468Ab1CKTCS (ORCPT ); Fri, 11 Mar 2011 14:02:18 -0500 X-IronPort-AV: E=McAfee;i="5400,1158,6282"; a="79266136" Message-ID: <4D7A71B9.9000306@codeaurora.org> Date: Fri, 11 Mar 2011 11:02:17 -0800 From: Abhijeet Dharmapurikar User-Agent: Thunderbird 2.0.0.22 (X11/20090608) MIME-Version: 1.0 To: Thomas Gleixner CC: davidb@codeaurora.org, "David S. Miller" , Andrew Morton , Bryan Huntsman , Daniel Walker , David Collins , Grant Likely , Greg Kroah-Hartman , Joe Perches , Russell King , Samuel Ortiz , Stepan Moskovchenko , Mark Brown , Linus Walleij , linux-arm-kernel@lists.infradead.org, linux-arm-msm@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [Qualcomm PM8921 MFD v2 2/6] mfd: pm8xxx: Add irq support References: <1299564590-30116-1-git-send-email-adharmap@codeaurora.org> <1299564590-30116-3-git-send-email-adharmap@codeaurora.org> <4D770E47.6050402@codeaurora.org> <4D79A85D.8000301@codeaurora.org> In-Reply-To: Content-Type: text/plain; charset=US-ASCII; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2696 Lines: 55 >> Yes however while updating the code I noticed that I would need to keep >> account of all the interrupts enabled and all the interrupts marked wakeup. >> This aids in switching to the wakeup set in the suspend callback and the >> enabled set in the resume callback. I will update the resume callback to >> enable the interrupts in irqs_allowed(the local state storage) in the next >> patch (my current patch does not do that). >> >> IOW I need to keep the local state storage. > > Wrong. The interrupts are disabled and reenabled by the core code and > not by some extra suspend/resume callbacks in your driver. The core > checks those marked as IRQ_WAKE, the wake callback to the irq chip is > only there if you need to set up some hardware register in order to > make the wake functionality work. So again, you don't need local state > as the core tracks the state for you. Help me understand this, the core code calls disable on all the interrupts while going to suspend. Notice that I have no disable callback, which means those interrupts remain unmasked. I could have a situation, when the system(a mobile phone) goes to suspend we dont want to wake it up because of unnecessary interrupts. A good example is, we want to wakeup the phone if the battery goes low, but dont want to wake it up if an acceleromter interrupt triggers. The drivers respectively mark the battery low interrupt as wakeup and the accelerometer interrupt as a non-wake up interrupt. Assume both of them are edge triggered interrupts. The genirq code does not mask the interrupt while going to suspend, it only calls disable(), which I understand should not mask the interrupt for check_wakeup_irqs() to work. If I don't mask that accelerometer interrupts in the interrupt controller's suspend() the phone will wakeup every time the user moves around, draining the battery unnecessarily. One might say that the accelerometer should be deactivated in the suspend callback of the accelerometer driver. Yes this can be done and we will not see an interrupt while suspended. However not all hardware can be deactivated like that. There are some devices which simply interrupt and the only way to keep from waking up is masking their interrupts. How do you suggest I mask the accelerometer interrupt? Abhijeet -- Sent by an employee of the Qualcomm Innovation Center, Inc. The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/