linux-kernel - Re: [PATCH v7 2/3] clk: introduce the common clock framework

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]

Date:	Fri, 23 Mar 2012 14:51:20 -0700
From:	Saravana Kannan <skannan@...eaurora.org>
To:	"Turquette, Mike" <mturquette@...com>
CC:	Shawn Guo <shawn.guo@...aro.org>, Paul Walmsley <paul@...an.com>,
	Russell King <linux@....linux.org.uk>,
	Linus Walleij <linus.walleij@...ricsson.com>,
	patches@...aro.org, Magnus Damm <magnus.damm@...il.com>,
	Sascha Hauer <s.hauer@...gutronix.de>,
	Mark Brown <broonie@...nsource.wolfsonmicro.com>,
	Stephen Boyd <sboyd@...eaurora.org>,
	linux-kernel@...r.kernel.org, linaro-dev@...ts.linaro.org,
	Jeremy Kerr <jeremy.kerr@...onical.com>,
	linux-arm-kernel@...ts.infradead.org,
	Arnd Bergman <arnd.bergmann@...aro.org>
Subject: Re: [PATCH v7 2/3] clk: introduce the common clock framework

On 03/23/2012 02:39 PM, Turquette, Mike wrote:
> On Fri, Mar 23, 2012 at 2:33 PM, Saravana Kannan<skannan@...eaurora.org>  wrote:
>> On 03/20/2012 08:10 PM, Saravana Kannan wrote:
>>>
>>> On 03/20/2012 04:53 PM, Turquette, Mike wrote:
>>>>
>>>> It does make me
>>>> wonder if it would be a good idea to pass in the parent rate for
>>>> .set_parent, which is analogous to .set_rate in many ways.
>>>
>>>
>>> I need to think a bit more about this.
>>
>>
>> I was thinking about this. I think the common clock fwk should let the
>> set_parent ops "return" the rate of the clock in addition to passing the
>> rate of the parent in.
>>
>> Say this is a divider clock and some one changes the parent. The cached
>> "rate" of the clock in the clock fwk is no longer correct. So, the clock fwk
>> should also add a "*new_rate" param to set parent ops.
>
> __clk_recalc_rates is called by __clk_reparent which is called by
> clk_set_parent.  __clk_recalc_rates is also called by clk_set_rate.
>
> Does this not handle the old cached clk->rate for you?
>

Yeah, I realized this just after I sent the email. I'm looking at the 
code to see if that's sufficient or not. Will get back soon.

-Saravana

-- 
Sent by an employee of the Qualcomm Innovation Center, Inc.
The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum.
--
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/