linux-kernel - Re: Query: When will drv->poweroff() called

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <4F30A668.8010407@st.com>
Date:	Tue, 7 Feb 2012 09:49:52 +0530
From:	Viresh Kumar <viresh.kumar@...com>
To:	"Rafael J. Wysocki" <rjw@...k.pl>, <amit.kucheria@...aro.org>
Cc:	"pavel@....cz" <pavel@....cz>,
	"len.brown@...el.com" <len.brown@...el.com>,
	"linux-pm@...ts.linux-foundation.org" 
	<linux-pm@...ts.linux-foundation.org>,
	"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
	Shiraz HASHIM <shiraz.hashim@...com>,
	Armando VISCONTI <armando.visconti@...com>,
	Vipin KUMAR <vipin.kumar@...com>,
	Deepak SIKRI <deepak.sikri@...com>,
	Vipul Kumar SAMAR <vipulkumar.samar@...com>,
	Amit VIRDI <Amit.VIRDI@...com>,
	Rajeev KUMAR <rajeev-dlh.kumar@...com>,
	Pratyush ANAND <pratyush.anand@...com>,
	Mirko GARDI <mirko.gardi@...com>,
	Vincenzo FRASCINO <Vincenzo.FRASCINO@...com>,
	Bhupesh SHARMA <bhupesh.sharma@...com>,
	"linux-arm-kernel@...ts.infradead.org" 
	<linux-arm-kernel@...ts.infradead.org>
Subject: Re: Query: When will drv->poweroff() called


Thanks Rafael.

On 2/6/2012 5:37 PM, Rafael J. Wysocki wrote:
> On Monday, February 06, 2012, Viresh Kumar wrote:
>> > 
>> > Hi Guys,
>> > 
>> > Sorry for asking this silly question, but i couldn't locate much
>> > help for it in documentation, so asking it.
>> > 
>> > We were testing hibernation for SPEAr13xx SoC family, based on
>> > ARM Cortex a9.
>> > 
>> > I observed that poweroff() callback of individual drivers are not
>> > getting called at all, while we test hibernate.
> They should be called in the last phase of hibernation, after the image
> has been created and the system is going for "power off" (hance the
> callback name).
> 
>> > I tried to go through the code to see what happened. It looked like
>> > there should be call to hibernation_set_ops() for platforms that are
>> > willing to get a call to poweroff() for their drivers.
> That's correct.  The ->poweroff() callbacks are only executed if
> hibernation_mode is equal to HIBERNATION_PLATFORM, which is not the
> default.
> 
>> > Otherwise shutdown of the busses gets called, which is a completely
>> > different path.
>> > 
>> > There are many drivers today, that are registering poweroff() from dev_pm_ops
>> > but are not doing bus specific shutdown stuff.
>> > 
>> > Even i tried to look for hibernation_set_ops() in kernel, and only acpi
>> > code is calling it.
> That's correct too.
> 
>> > I didn't understood how other ARM Sub-Arch's are handling this.
> Well, they are supposed to call hibernation_set_ops() and set the operations
> appropriately.  Those operations may be empty routines if they don't need
> to do anything, but they have to be defined.

Hi Amit,

Can you give some input on why none of the ARM platforms are calling
this routine currently.

-- 
viresh
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/