From mboxrd@z Thu Jan  1 00:00:00 1970
From: wuyun.wu@huawei.com (Yun Wu (Abel))
Date: Sat, 31 Jan 2015 09:43:16 +0800
Subject: [PATCH 5/5] irqchip: gicv3-its: add support for power down
In-Reply-To: <54CBDA14.3010503@arm.com>
References: <1422604009-9248-1-git-send-email-wuyun.wu@huawei.com>
 <1422604009-9248-6-git-send-email-wuyun.wu@huawei.com>
 <54CBDA14.3010503@arm.com>
Message-ID: <54CC3334.9010705@huawei.com>
To: linux-arm-kernel@lists.infradead.org
List-Id: linux-arm-kernel.lists.infradead.org

On 2015/1/31 3:23, Marc Zyngier wrote:

> 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.
> 

Sure, checking the ITS state before initializing it is really a better
solution, I will rewrite this patch and test again.

Thanks,
	Abel