From mboxrd@z Thu Jan 1 00:00:00 1970 From: Thomas Gleixner Subject: Re: Seeking clarity on IRQCHIP_MASK_ON_SUSPEND Date: Mon, 10 Sep 2012 12:28:35 +0200 (CEST) Message-ID: References: <20120910165127.37dd07f3@notabene.brown> Mime-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Return-path: Received: from www.linutronix.de ([62.245.132.108]:49150 "EHLO Galois.linutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751509Ab2IJK2i (ORCPT ); Mon, 10 Sep 2012 06:28:38 -0400 In-Reply-To: <20120910165127.37dd07f3@notabene.brown> Sender: linux-omap-owner@vger.kernel.org List-Id: linux-omap@vger.kernel.org To: NeilBrown Cc: "Rafael J. Wysocki" , "Shilimkar, Santosh" , lkml , linux-omap@vger.kernel.org, Kevin Hilman On Mon, 10 Sep 2012, NeilBrown wrote: > > The IRQCHIP_MASK_ON_SUSPEND flag seems to be hard to use correctly, so either > I'm understanding it wrongly, or it could be made easier to use. > If the first case, I'm hoping that some improvement to documentation might > result. If the second, then maybe we can fix the code. ... > Is anyone able to give a definitive answer on this? Should > IRQCHIP_MASK_ON_SUSPEND be removed? The whole point of IRQCHIP_MASK_ON_SUSPEND is to deal with hardware designed by geniuses. Most SoCs have a way to mark the interrupts which serve as a wake up source as such. All other interrupts are magically "masked" on entry to suspend. Now there is hardware which is missing such a control, so we need to mask the non wakeup interrupts right before going into suspend. That's what IRQCHIP_MASK_ON_SUSPEND does. Not more, not less. See commit d209a699a0b for more ugly details. You might be looking for a different functionality. Can you explain what you need? Thanks, tglx