From mboxrd@z Thu Jan 1 00:00:00 1970 From: Pavel Machek Subject: Re: [PATCH 0/2][RFC] PM / sleep: Expose DPM watchdog timeout to sysfs Date: Thu, 11 Aug 2016 20:54:42 +0200 Message-ID: <20160811185441.GA15813@amd> References: Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Received: from atrey.karlin.mff.cuni.cz ([195.113.26.193]:54718 "EHLO atrey.karlin.mff.cuni.cz" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751260AbcHKSyp (ORCPT ); Thu, 11 Aug 2016 14:54:45 -0400 Content-Disposition: inline In-Reply-To: Sender: linux-pm-owner@vger.kernel.org List-Id: linux-pm@vger.kernel.org To: Chen Yu Cc: Linux PM List , "Rafael J. Wysocki" , Greg Kroah-Hartman , Len Brown , Takashi Iwai , Benoit Goby Hi! > Recently we have a new report that, the harddisk can not > resume on time due to firmware issues, and got a kernel > panic because of DPM watchdog timeout. Since the default > timeout has once been modified from 12 to 60 seconds, we > might still encounter new case which requires a longer timeout, > so expose the value to sysfs and let the users decide which > value is appropriate, meanwhile this can also ease the debugging > process. > > The first patch is to force DPM watchdog depending on CONFIG_PM_SLEEP, > thus the second patch which does the actual work, can use > CONFIG_DPM_WATCHDOG safely without checking CONFIG_PM_SLEEP. Kernel should just work. User should not have to configure random knobs to have working suspend/hibernation. We do not want "CONFIG_BREAK_SUSPEND" so I believe we don't want "CONFIG_DPM_WATCHDOG". If normal users select it and it breaks their system, make it depend on "CONFIG_EXPERT" or hide it in some other way or maybe remove it from Kconfig altogether. Or maybe CONFIG_DPM_WATCHDOG should contain numeric value that user has to select? And I'm pretty certain new user interfaces need to be documented. NAK. Pavel > Chen Yu (2): > PM / sleep: Make DPM watchdog depend on PM_SLEEP > PM / Sleep: Expose DPM watchdog timeout to sysfs > > drivers/base/power/main.c | 4 +++- > include/linux/sched/sysctl.h | 4 ++++ > kernel/power/Kconfig | 2 +- > kernel/sysctl.c | 16 ++++++++++++++++ > 4 files changed, 24 insertions(+), 2 deletions(-) > -- (english) http://www.livejournal.com/~pavelmachek (cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html