From mboxrd@z Thu Jan  1 00:00:00 1970
From: arnd@arndb.de (Arnd Bergmann)
Date: Thu, 07 May 2015 11:43:15 +0200
Subject: [Discussion] how to implement external power down for ARM
In-Reply-To: <554B2DF5.4040600@huawei.com>
References: <55417F5A.4040300@linaro.org> <20501959.OF3FLWO2Eh@wuerfel>
 <554B2DF5.4040600@huawei.com>
Message-ID: <4412805.fx6caR2qJ7@wuerfel>
To: linux-arm-kernel@lists.infradead.org
List-Id: linux-arm-kernel.lists.infradead.org

On Thursday 07 May 2015 17:18:45 Shannon Zhao wrote:
> On 2015/5/7 16:55, Arnd Bergmann wrote:
> > On Thursday 07 May 2015 10:39:35 Shannon Zhao wrote:
> >> I tried Ubuntu Trusty from Christoffer, when typing "system_powerdown"
> >> on QEMU monitor, "cat /dev/input/event0 | hexdump" shows the event is
> >> triggered but the guest doesn't poweroff.
> > 
> > Can you try installing acpid by running 'sudo apt-get install acpid' in
> > the image? I suspect it should just work by scanning the event devices
> > even in the absence of ACPI on the platform.
> > 
> 
> Cool, I start acpid and the poweroff works.

Ok, great, thanks for confirming this! Have you tried reboot as well?

>>From looking at the acpid source code, I suspect it does not work unless
extra configuration files are added, but that would be the same as for the
ACPI case.

	Arnd