linux-kernel - Re: [PATCH v3] PM / OPP: discard duplicate OPPs

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:	Tue, 20 May 2014 19:06:29 +0530
From:	Viresh Kumar <viresh.kumar@...aro.org>
To:	Nishanth Menon <nm@...com>
Cc:	Chander Kashyap <chander.kashyap@...aro.org>,
	"linux-pm@...r.kernel.org" <linux-pm@...r.kernel.org>,
	Linux Kernel Mailing List <linux-kernel@...r.kernel.org>,
	"Rafael J. Wysocki" <rjw@...ysocki.net>,
	Pavel Machek <pavel@....cz>,
	"Brown, Len" <len.brown@...el.com>,
	Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
	Chander Kashyap <k.chander@...sung.com>,
	Inderpal Singh <inderpal.s@...sung.com>
Subject: Re: [PATCH v3] PM / OPP: discard duplicate OPPs

On 20 May 2014 18:02, Nishanth Menon <nm@...com> wrote:
>> +               if (new_opp->u_volt == opp->u_volt)
>> +                       ret = -EEXIST;

As I mentioned in the other mail in same thread, I screwed up
again. I meant a s/==/!= here..

In words:
- If we are adding duplicate OPPs (both freq/volt same), return 0 as
we already have that.
- if we are adding OPPs with same key (same freq, diff volt), return
-EEXIST and also print both old and new values of both freq and volt.

> Else -> we now have two OPPs with the same key (same frequency, but
> different voltage) -> That does not make sense.
> Example: why would you add:
> If you already had {1GHz, 1.2V}
> and you attempted:
> {1GHz, 1.1V} (if you could do that, then you should added {1GHz, 1.1V}
> in the first place)
> OR
> {1GHz, 1.3V} (if you could do that, then you should add {1GHz, 1.3V}
> and the {1GHz, 1.2V} is wrong)

Exactly, this is why I wanted to return -EEXIST here with some prints.
--
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/