From mboxrd@z Thu Jan 1 00:00:00 1970 From: Brian Norris Subject: Re: [PATCH] PM / sleep: add configurable delay for pm_test Date: Thu, 4 Sep 2014 10:54:50 -0700 Message-ID: <20140904175450.GB18411@ld-irv-0074> References: <1409788535-28264-1-git-send-email-computersforpeace@gmail.com> <20140904071412.GA29832@amd> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Received: from mail-pd0-f171.google.com ([209.85.192.171]:64911 "EHLO mail-pd0-f171.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751689AbaIDRy5 (ORCPT ); Thu, 4 Sep 2014 13:54:57 -0400 Content-Disposition: inline In-Reply-To: <20140904071412.GA29832@amd> Sender: linux-pm-owner@vger.kernel.org List-Id: linux-pm@vger.kernel.org To: Pavel Machek Cc: "Rafael J. Wysocki\"" , Linux Kernel , linux-pm@vger.kernel.org, Len Brown On Thu, Sep 04, 2014 at 09:14:12AM +0200, Pavel Machek wrote: > > When CONFIG_PM_DEBUG=y, we provide a sysfs file (/sys/power/pm_test) for > > selecting one of a few suspend test modes, where rather than entering a > > full suspend state, the kernel will perform some subset of suspend > > steps, wait 5 seconds, and then resume back to normal operation. > > > > This mode is useful for (among other things) observing the state of the > > system just before entering a sleep mode, for debugging or analysis > > purposes. However, a constant 5 second wait is not sufficient for some > > sorts of analysis; for example, on an SoC, one might want to use > > external tools to probe the power states of various on-chip controllers > > or clocks. > > When you are doing this kind of analysis, perhaps directly modifying > kernel source is the way to go ...? That's what I've been doing for now, but I have a few engineers who need to do this sort of testing and aren't kernel developers. I could continue to maintain my own patch for this, but I just thought I'd see what others thought. Is there a good reason this can't be in mainline? These features are hidden behind a Kconfig symbol called PM_DEBUG anyway, and I think this classifies as a pretty simple extension to the limited existing PM debugging options. Regards, Brian