public inbox for linuxppc-dev@ozlabs.org 
 help / color / mirror / Atom feed
From: olof@lixom•net (Olof Johansson)
To: paulus@samba•org, linuxppc-dev@ozlabs•org, egor@pasemi•com,
	arnd@arndb•de, cpufreq@lists•linux.org.uk
Subject: Re: [PATCH v3] [2.6.22] pasemi: cpufreq driver
Date: Sat, 28 Apr 2007 23:42:37 -0500	[thread overview]
Message-ID: <20070429044237.GB7478@lixom.net> (raw)
In-Reply-To: <20070429025021.GC2781@isilmar.linta.de>

On Sat, Apr 28, 2007 at 10:50:21PM -0400, Dominik Brodowski wrote:
> Hi,
> 
> On Fri, Apr 27, 2007 at 12:46:01AM -0500, Olof Johansson wrote:
> > +	max_freq = (u32*) get_property(cpu, "clock-frequency", NULL);
> 
> (u32) or (32*) ?
> 
> > +	cur_astate = get_cur_astate(policy->cpu);
> 
> May the different cores have different settings at initalization? e.g.
> 
> core 0:		freq A
> core 1:		freq B
> 
> with (freq B > freq A)? If so, cur_astate is set wrongly, as the _effective_
> frequency would be freq B, right?

Firmware normally sets only cpu 0 (since cpu 1 isn't started until after
linux is loaded and started). So it'll works well by default.

> > +#ifndef CONFIG_PPC_PASEMI_CPUFREQ
> > +	printk(KERN_WARNING "No cpufreq driver, powersavings modes disabled\n");
> > +	current_mode = 0;
> > +#endif
> > +
> 
> This confuses me a bit -- does something else than cpufreq not work if
> cpufreq is disabled?

After doze, we come back out in astate 0, so we need to raise it back
up. We do so by calling the restore_astate() function. If we don't have
it, and use idle=doze, we'll end up with a cpu running at astate 0 and
no way to raise it.

> Overall, the patch looks good to me.


Thanks,

-Olof

      parent reply	other threads:[~2007-04-29  4:41 UTC|newest]

Thread overview: 29+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2007-04-25 20:46 [PATCH] [2.6.22] pasemi: cpufreq driver Olof Johansson
2007-04-25 23:47 ` Arnd Bergmann
2007-04-25 23:57   ` Olof Johansson
2007-04-26  1:57     ` Olof Johansson
2007-04-26  6:56   ` cbe_cpufreq crashes my machine Olof Johansson
2007-04-26  8:39     ` Benjamin Herrenschmidt
2007-04-26 23:07     ` [PATCH] cell: cbe_cpufreq cleanup and crash fix Olof Johansson
2007-04-27  5:22       ` [Cbe-oss-dev] " Akinobu Mita
2007-04-27  5:32         ` Olof Johansson
2007-04-27  5:33       ` [PATCH v2] " Olof Johansson
2007-04-27  7:55         ` Christian Krafft
2007-04-26  5:37 ` [PATCH v2] [2.6.22] pasemi: cpufreq driver Olof Johansson
2007-04-26  8:55   ` Arnd Bergmann
2007-04-26 16:48     ` Olof Johansson
2007-04-26 17:11       ` Arnd Bergmann
2007-04-26 19:05         ` Segher Boessenkool
2007-04-26 20:38           ` Olof Johansson
2007-04-27  0:10             ` Segher Boessenkool
2007-04-26 20:26         ` Olof Johansson
2007-04-26 20:43           ` Arnd Bergmann
2007-04-26 10:26   ` Johannes Berg
2007-04-26 20:37     ` Olof Johansson
2007-04-27  9:40       ` Johannes Berg
2007-04-27 18:09         ` Olof Johansson
2007-04-27  5:46   ` [PATCH v3] " Olof Johansson
2007-04-29  2:50     ` Dominik Brodowski
2007-04-29  3:40       ` Stephen Rothwell
2007-04-29  4:39         ` Olof Johansson
2007-04-29  4:42       ` Olof Johansson [this message]

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20070429044237.GB7478@lixom.net \
    --to=olof@lixom$(echo .)net \
    --cc=arnd@arndb$(echo .)de \
    --cc=cpufreq@lists$(echo .)linux.org.uk \
    --cc=egor@pasemi$(echo .)com \
    --cc=linuxppc-dev@ozlabs$(echo .)org \
    --cc=paulus@samba$(echo .)org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox