From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1762817AbbA3TXM (ORCPT ); Fri, 30 Jan 2015 14:23:12 -0500 Received: from foss-mx-na.foss.arm.com ([217.140.108.86]:46754 "EHLO foss-mx-na.foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752259AbbA3TXK (ORCPT ); Fri, 30 Jan 2015 14:23:10 -0500 Message-ID: <54CBDA14.3010503@arm.com> Date: Fri, 30 Jan 2015 19:23:00 +0000 From: Marc Zyngier User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Icedove/31.3.0 MIME-Version: 1.0 To: Yun Wu , "tglx@linutronix.de" , "jason@lakedaemon.net" CC: "linux-kernel@vger.kernel.org" , "linux-arm-kernel@lists.infradead.org" Subject: Re: [PATCH 5/5] irqchip: gicv3-its: add support for power down References: <1422604009-9248-1-git-send-email-wuyun.wu@huawei.com> <1422604009-9248-6-git-send-email-wuyun.wu@huawei.com> In-Reply-To: <1422604009-9248-6-git-send-email-wuyun.wu@huawei.com> Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 30/01/15 07:46, Yun Wu wrote: > Configurations of an ITS cannot be changed if the ITS is in an > active status, so it might not be safe to perform a soft reboot > with all the active ITSes un-disabled, etc. kexec. > > This patch will make sure all the active ITSes disabled before > enabling them again without resetting ITS hardware. And what happens if the kernel crashes or gets rebooted from a watchdog? Or if the bootloader messes things up? The ITS is in an unknown state when we start again. Wouldn't it be better to address this instead? Enforcing an safe initial state seems a better solution that relying on mechanisms that may not be relevant for all cases. Thanks, M. -- Jazz is not dead. It just smells funny...