From: Jamie Lokier <lk@tantalophile.demon.co.uk>
To: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Linus Torvalds <torvalds@transmeta.com>,
Padraig Brady <padraig@antefacto.com>,
linux-kernel@vger.kernel.org
Subject: Re: CPU frequency shifting "problems"
Date: Fri, 28 Sep 2001 23:24:58 +0100 [thread overview]
Message-ID: <20010928232458.A15016@kushida.degree2.com> (raw)
In-Reply-To: <Pine.LNX.4.33.0109280902250.1682-100000@penguin.transmeta.com> <m11ykr5a9y.fsf@frodo.biederman.org>
In-Reply-To: <m11ykr5a9y.fsf@frodo.biederman.org>; from ebiederm@xmission.com on Fri, Sep 28, 2001 at 02:29:45PM -0600
Eric W. Biederman wrote:
> > What does exist is the bus clock (well, a multiple of it, but you get the
> > idea), and that one is stable. I bet PCI devices don't like to be randomly
> > driven at frequencies "somewhere between 12 and 33MHz" depending on load ;)
>
> I doubt they would like it but it is perfectly legal (PCI spec..) to
> vary the pci clock, depending upon load.
Yes it is. Also, the PCI clock is frequency modulated to reduce
electrical interference. (Or on a more cynical note, to pass the
official emissions tests ;-)
However it's common practice to PLL to the PCI clock, for clock
distribution on a board, so varying the frequency must be done in a
strictly constrained fashion.
-- Jamie
next prev parent reply other threads:[~2001-09-28 22:25 UTC|newest]
Thread overview: 69+ messages / expand[flat|nested] mbox.gz Atom feed top
2001-09-25 17:49 Locking comment on shrink_caches() Marcelo Tosatti
2001-09-25 19:57 ` David S. Miller
2001-09-25 18:40 ` Marcelo Tosatti
2001-09-25 20:40 ` Josh MacDonald
2001-09-25 19:25 ` Marcelo Tosatti
2001-09-25 20:15 ` David S. Miller
2001-09-25 19:02 ` Marcelo Tosatti
2001-09-25 20:24 ` Rik van Riel
2001-09-25 22:26 ` David S. Miller
2001-09-26 17:42 ` Ingo Molnar
2001-09-25 20:28 ` David S. Miller
2001-09-25 21:05 ` Andrew Morton
2001-09-25 21:48 ` David S. Miller
2001-09-25 20:29 ` David S. Miller
2001-09-25 21:00 ` Benjamin LaHaise
2001-09-25 22:03 ` Andrea Arcangeli
2001-09-25 21:55 ` David S. Miller
2001-09-25 22:16 ` Benjamin LaHaise
2001-09-25 22:28 ` David S. Miller
2001-09-26 16:40 ` Alan Cox
2001-09-26 17:25 ` Linus Torvalds
2001-09-26 17:40 ` Alan Cox
2001-09-26 17:44 ` Linus Torvalds
2001-09-26 18:01 ` Benjamin LaHaise
2001-09-26 18:01 ` Dave Jones
2001-09-26 20:20 ` Vojtech Pavlik
2001-09-26 20:24 ` Vojtech Pavlik
2001-09-26 17:45 ` Dave Jones
2001-09-26 17:50 ` Alan Cox
2001-09-26 17:59 ` Dave Jones
2001-09-26 18:07 ` Alan Cox
2001-09-26 18:09 ` Padraig Brady
2001-09-26 18:22 ` Dave Jones
2001-09-26 18:24 ` Linus Torvalds
2001-09-26 18:40 ` Dave Jones
2001-09-26 19:12 ` Linus Torvalds
2001-09-27 12:22 ` CPU frequency shifting "problems" Padraig Brady
2001-09-27 12:44 ` Dave Jones
2001-09-27 23:23 ` Linus Torvalds
2001-09-28 0:55 ` Alan Cox
2001-09-28 2:12 ` Stefan Smietanowski
2001-09-28 8:55 ` Jamie Lokier
2001-09-28 16:11 ` Linus Torvalds
2001-09-28 20:29 ` Eric W. Biederman
2001-09-28 22:24 ` Jamie Lokier [this message]
2001-09-26 19:04 ` Locking comment on shrink_caches() George Greer
2001-09-26 18:59 ` George Greer
2001-09-26 17:43 ` Richard Gooch
2001-09-26 18:24 ` Benjamin LaHaise
2001-09-26 18:48 ` Richard Gooch
2001-09-26 18:58 ` Davide Libenzi
2001-09-26 23:26 ` David S. Miller
2001-09-27 12:10 ` Alan Cox
2001-09-27 15:38 ` Linus Torvalds
2001-09-27 17:44 ` Ingo Molnar
2001-09-27 19:41 ` David S. Miller
2001-09-27 22:59 ` Alan Cox
2001-09-25 22:01 ` Andrea Arcangeli
2001-09-25 22:03 ` David S. Miller
2001-09-25 22:59 ` Andrea Arcangeli
2001-09-25 21:57 ` Andrea Arcangeli
2001-09-28 1:24 CPU frequency shifting "problems" Grover, Andrew
2001-09-28 21:54 ` Linus Torvalds
2001-09-29 0:37 ` Jonathan Morton
2001-09-28 22:30 ` Alan Cox
2001-10-01 9:28 ` Pavel Machek
2001-09-28 22:47 Grover, Andrew
2001-09-29 1:10 ` Gerhard Mack
[not found] <8FB7D6BCE8A2D511B88C00508B68C2081971E4@orsmsx102.jf.intel.com>
2001-09-28 23:09 ` Alan Cox
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=20010928232458.A15016@kushida.degree2.com \
--to=lk@tantalophile.demon.co.uk \
--cc=ebiederm@xmission.com \
--cc=linux-kernel@vger.kernel.org \
--cc=padraig@antefacto.com \
--cc=torvalds@transmeta.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
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
all inboxes | Powered by JetHome®