From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Rafael J. Wysocki" Subject: Re: PM interface to suspend/resume individual/specific device Date: Sun, 5 Jul 2009 23:30:48 +0200 Message-ID: <200907052330.48382.rjw@sisk.pl> References: Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: Content-Disposition: inline List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: linux-pm-bounces@lists.linux-foundation.org Errors-To: linux-pm-bounces@lists.linux-foundation.org To: HU TAO-TGHK48 Cc: linux-pm@lists.linux-foundation.org List-Id: linux-pm@vger.kernel.org On Sunday 05 July 2009, HU TAO-TGHK48 wrote: > Below command would suspend all of devices and system > # echo mem > /sys/power/state > > How to just suspend/resume one specific devices? E.g. > /sys/devices/platform/serial8250 > > It would be useful to test the stability of PM interface of individual > driver. > If drivers called earlier refuse to suspend then not able to reach the > suspend/resume function of the specific driver. > > And it would be useful for automatic testing since a script can > suspend/resume the specific device for many times without manual > operation. > > Is it possible to add "state" for each device? > E.g. > # echo mem > /sys/devices/platform/serial8250/power/state No, and you can't suspend individual devices in general. There is such a mechanism for USB devices. The problem is that suspend while entering a system sleep state is generally a different operation from a suspend done at run time and the latter wouldn't be suitable for testing the former. If you need to test the suspend-resume of a driver, please use the /sys/power/pm_test interface (it works on the entire system, but it doesn't complete the suspend, so it's suitable for testing). Thanks, Rafael