From: Matthew Garrett <mjg59@srcf.ucam.org>
To: Richard Purdie <rpurdie@rpsys.net>
Cc: Henrique de Moraes Holschuh <hmh@hmh.eng.br>,
Andrew Morton <akpm@linux-foundation.org>,
linux-acpi@vger.kernel.org, "Rafael J. Wysocki" <rjw@sisk.pl>
Subject: Re: brightness control on thinkpad t61p
Date: Tue, 8 Jan 2008 15:54:01 +0000 [thread overview]
Message-ID: <20080108155401.GA4954@srcf.ucam.org> (raw)
In-Reply-To: <1199807102.6053.31.camel@localhost.localdomain>
On Tue, Jan 08, 2008 at 03:45:02PM +0000, Richard Purdie wrote:
> I did't get enough context above but I went through the archives and it
> seems this is about linearising backlight values.
Indeed. The ACPI spec provides a range of 0-100, without specifying what
this actually means (it gives brightness and power consumption as two
different examples). Implementations are only required to support a
subset of these, with the others being ignored. The current hook into
the backlight class exports this range but provides no means for an
application to determine which values are valid - I'd prefer to just
flatten the range to remove the holes. Given the lack of standardisation
in the real meaning of the values, I don't think exporting the 0-100
range buys us anything.
--
Matthew Garrett | mjg59@srcf.ucam.org
next prev parent reply other threads:[~2008-01-08 15:54 UTC|newest]
Thread overview: 25+ messages / expand[flat|nested] mbox.gz Atom feed top
2007-12-23 8:00 brightness control on thinkpad t61p Andrew Morton
2007-12-23 12:16 ` Rafael J. Wysocki
2007-12-24 7:34 ` Matthew Garrett
2007-12-24 17:14 ` Henrique de Moraes Holschuh
2007-12-26 22:10 ` Andrew Morton
2007-12-26 22:23 ` Matthew Garrett
2007-12-27 12:33 ` Henrique de Moraes Holschuh
2008-01-07 1:36 ` Henrique de Moraes Holschuh
2008-01-07 19:48 ` Matthew Garrett
2008-01-08 0:32 ` Henrique de Moraes Holschuh
2008-01-08 0:45 ` Matthew Garrett
2008-01-08 12:06 ` Henrique de Moraes Holschuh
2008-01-08 12:18 ` Matthew Garrett
2008-01-08 12:48 ` Henrique de Moraes Holschuh
2008-01-08 15:17 ` Matthew Garrett
2008-01-08 15:45 ` Richard Purdie
2008-01-08 15:54 ` Matthew Garrett [this message]
2008-01-08 16:29 ` Richard Purdie
2008-01-08 16:49 ` Henrique de Moraes Holschuh
2008-01-08 16:56 ` Richard Purdie
2008-01-08 17:36 ` Henrique de Moraes Holschuh
2007-12-27 12:31 ` Henrique de Moraes Holschuh
2007-12-24 17:08 ` Henrique de Moraes Holschuh
2007-12-26 22:10 ` Andrew Morton
2007-12-27 13:15 ` Henrique de Moraes Holschuh
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=20080108155401.GA4954@srcf.ucam.org \
--to=mjg59@srcf.ucam.org \
--cc=akpm@linux-foundation.org \
--cc=hmh@hmh.eng.br \
--cc=linux-acpi@vger.kernel.org \
--cc=rjw@sisk.pl \
--cc=rpurdie@rpsys.net \
/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