linux-kernel - Re: [PATCH v2] PM / devfreq: Use freq_table for available

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] [day] [month] [year] [list]

Date:	Mon, 05 May 2014 11:18:35 -0700
From:	Saravana Kannan <skannan@...eaurora.org>
To:	myungjoo.ham@...sung.com
CC:	박경민 <kyungmin.park@...sung.com>,
	"linux-pm@...r.kernel.org" <linux-pm@...r.kernel.org>,
	"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
	"linux-arm-msm@...r.kernel.org" <linux-arm-msm@...r.kernel.org>,
	"linux-arm-kernel@...ts.infradead.org" 
	<linux-arm-kernel@...ts.infradead.org>
Subject: Re: [PATCH v2] PM / devfreq: Use freq_table for available_frequencies

On 04/29/2014 01:00 PM, Saravana Kannan wrote:
> On 04/27/2014 06:41 PM, MyungJoo Ham wrote:
>> You are hereby changing the semmantics of the original
>> available_frequencies node.
>>
>> When a frequency/voltage pair has been disabled (opp_disable), probably
>> by opp_disable(), the frequency is no more "available".
>> However, when the driver author supplied freq_table as well as OPP
>> in order to see the statistics, the node will behave differently.
>>
>> Please do not affect the current users as long as it does not give
>> additional benefit or fix a bug.
> 
> I was actually trying to stick with the semantics as it was documented.
> The documentation for this file says it'll show frequencies that are not
> allowed by the current min/max settings either. To me, an OPP disable
> seems similar to some frequencies "disabled" by min/max settings.
> 
> Giving preference to OPP is not a hard change to do, but it seems to go
> againsts the documented semantics.
> 
> Thoughts?

I'll send out another patch like you wanted -- with OPP being given
preference over freq_table when listing frequencies.

But I would still like to hear your thoughts. As of today, there's no
clean way to get the complete list of available frequencies that would
give a consistent output irrespective of the temporary limits/conditions
imposed by thermal, current limiting, etc. The round about way is to cat
trans_stat and parse the frequencies from that.

That's why I was trying to give preference to freq_table.

Thanks,
Saravana

-- 
The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
hosted by The Linux Foundation
--
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/