From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934156Ab0J1SxR (ORCPT ); Thu, 28 Oct 2010 14:53:17 -0400 Received: from www.tglx.de ([62.245.132.106]:48747 "EHLO www.tglx.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933400Ab0J1SxL (ORCPT ); Thu, 28 Oct 2010 14:53:11 -0400 Date: Thu, 28 Oct 2010 20:52:54 +0200 (CEST) From: Thomas Gleixner To: Abhijeet Dharmapurikar cc: Ingo Molnar , "H. Peter Anvin" , linux-kernel@vger.kernel.org, linux-arm-msm-owner@vger.kernel.org Subject: Re: [RFC IRQ] genirq: fix handle_nested_irq for lazy disable In-Reply-To: <4CC9B167.8010401@codeaurora.org> Message-ID: References: <1288144209-28086-1-git-send-email-adharmap@codeaurora.org> <4CC9B167.8010401@codeaurora.org> User-Agent: Alpine 2.00 (LFD 1167 2008-08-23) MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, 28 Oct 2010, Abhijeet Dharmapurikar wrote: > Thomas Gleixner wrote: > > Aside of that this wont work for edge triggered interrupts, as you'd > > loose the edge, so this needs more thought and a thorough look at the > > users of handle_nested_irq(). > > I didn't understand this though. This patch will mask the interrupt in the > controller even if it were edge. My interrupt controller latches > edges and wants a mask (or an ack) to be executed to deactivate the line > summary line. Do you mean that I should mark the interrupt IRQ_PENDING if it > were an edge before masking it? If not, can you please explain. See handle_edge_irq(). An edge is a one time event. Once you mask/ack it, it's gone. So now when you unmask it won't reissue the interrupt on the hardware level. Level interrupts do, as the mask does not affect that. Thanks, tglx