Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753137Ab0LaKj1 (ORCPT ); Fri, 31 Dec 2010 05:39:27 -0500 Received: from wolverine01.qualcomm.com ([199.106.114.254]:19022 "EHLO wolverine01.qualcomm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751913Ab0LaKj0 (ORCPT ); Fri, 31 Dec 2010 05:39:26 -0500 X-IronPort-AV: E=McAfee;i="5400,1158,6212"; a="68826241" Message-ID: <4D1DB2DD.3020701@codeaurora.org> Date: Fri, 31 Dec 2010 02:39:25 -0800 From: Abhijeet Dharmapurikar User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.9.2.13) Gecko/20101208 Thunderbird/3.1.7 MIME-Version: 1.0 To: Rabin Vincent CC: Russell King , Chao Xie , Daniel Walker , linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] GIC: Assign correct flow handler type in set_type callback References: <1293686960-12581-1-git-send-email-adharmap@codeaurora.org> In-Reply-To: Content-Type: text/plain; charset=ISO-8859-1; 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: 1709 Lines: 38 On 12/29/2010 10:27 PM, Rabin Vincent wrote: > On Thu, Dec 30, 2010 at 10:59 AM, Abhijeet Dharmapurikar > wrote: >> There are some interrupts that are true edge triggered in nature. If not >> marked IRQ_PENDING, when disabled, they will be lost. >> >> Use the set_type callback to assign the correct flow type handler for >> shared peripheral interrupts. >> >> Signed-off-by: Abhijeet Dharmapurikar >> --- >> This came to light when a edge triggered interrupt was supposed to wakeup the >> sytem. The flow handler was set to the default handle_level_irq. On the resume >> path the flow handler was invoked right after the I bit was cleared but before >> each individual interrupts were enabled. This made the handle_level_irq ignore > > Why does the flow handler hit when the interrupt is disabled? Have you set > IRQF_NOSUSPEND on this interrupt? > Since GIC doesnt have disable callback it implements lazy disabling. The interrupt is only marked IRQ_DISABLED in the descriptor but is not masked in the GIC. Hence the interrupt flow handler is hit. Now that I re-read the code setting IRQF_NO_SUSPEND would fix the issue. But shouldnt set_irq_wake() do something similar? Do I need to request IRQF_NO_SUSPEND for all the interrupts that could possibly wakeup the system - seems a bit unnecessary. IMO the interrupt should not be disabled if it is marked IRQF_NO_SUPEND || IRQ_WAKEUP is set. Abhijeet -- 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/