From: Matthew Garrett <mjg59@srcf.ucam.org>
To: Seth Forshee <seth.forshee@canonical.com>
Cc: Len Brown <lenb@kernel.org>, "Rafael J. Wysocki" <rjw@sisk.pl>,
linux-acpi@vger.kernel.org, Ben Jencks <ben@bjencks.net>,
joeyli <jlee@suse.com>
Subject: Re: [PATCH] ACPI: Disable Windows 8 compatibility for some Lenovo ThinkPads
Date: Mon, 11 Feb 2013 17:52:13 +0000 [thread overview]
Message-ID: <20130211175213.GA25139@srcf.ucam.org> (raw)
In-Reply-To: <1360599681-24781-1-git-send-email-seth.forshee@canonical.com>
On Mon, Feb 11, 2013 at 10:21:21AM -0600, Seth Forshee wrote:
> The AML implementation for brightness control on several ThinkPads
> contains a workaround to meet a Windows 8 requirement of 101 brightness
> levels [1]. The implementation is flawed, as only 16 of the brighness
> values reported by _BCL affect a change in brightness. _BCM silently
> discards the rest of the values. Disabling Windows 8 compatibility on
> these machines reverts them to the old behavior, making _BCL only report
> the 16 brightness levels which actually work. Add a quirk to do this
> along with a dmi callback to disable Win8 compatibility.
So the problem is that userspace is writing values that don't happen to
be aligned with the values the hardware reacts to, and so nothing gets
changed?
--
Matthew Garrett | mjg59@srcf.ucam.org
next prev parent reply other threads:[~2013-02-11 17:52 UTC|newest]
Thread overview: 69+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-02-11 16:21 [PATCH] ACPI: Disable Windows 8 compatibility for some Lenovo ThinkPads Seth Forshee
2013-02-11 17:52 ` Matthew Garrett [this message]
2013-02-11 19:06 ` Seth Forshee
2013-02-11 19:09 ` Matthew Garrett
2013-02-11 19:31 ` Rafael J. Wysocki
2013-02-12 3:05 ` Seth Forshee
2013-02-13 20:32 ` Seth Forshee
2013-02-13 20:55 ` Matthew Garrett
2013-02-13 21:04 ` Ben Jencks
2013-02-13 21:49 ` Seth Forshee
2013-02-13 21:46 ` Seth Forshee
2013-02-13 21:54 ` Matthew Garrett
2013-02-13 22:04 ` Seth Forshee
2013-03-07 19:38 ` Seth Forshee
2013-03-07 19:39 ` [PATCH 1/5] ACPICA: Add interface for getting latest Windows version requested via _OSI Seth Forshee
2013-03-07 19:39 ` [PATCH 2/5] acpi_video: Avoid unnecessary conversions between backlight levels and indexes Seth Forshee
2013-03-07 19:39 ` [PATCH 3/5] acpi_video: Add workaround for broken Windows 8 backlight implementations Seth Forshee
2013-04-04 11:44 ` Aaron Lu
2013-04-04 12:35 ` Seth Forshee
2013-04-04 13:46 ` Aaron Lu
2013-04-04 14:02 ` Seth Forshee
2013-04-04 14:27 ` Aaron Lu
2013-03-07 19:39 ` [PATCH 4/5] acpi_video: Disable use of _BQC when value doesn't match those set through _BCM Seth Forshee
2013-03-07 19:39 ` [PATCH 5/5] acpi_video: Don't handle ACPI brightness notifications by default Seth Forshee
2013-08-02 5:55 ` Aaron Lu
2013-08-02 14:41 ` Rafael J. Wysocki
2013-08-02 14:52 ` Aaron Lu
2013-08-03 0:26 ` Rafael J. Wysocki
2013-08-03 9:46 ` Aaron Lu
2013-08-03 11:23 ` Rafael J. Wysocki
2013-08-03 12:10 ` Aaron Lu
2013-08-03 22:07 ` Rafael J. Wysocki
2013-08-04 1:08 ` Aaron Lu
2013-03-18 21:25 ` [PATCH] ACPI: Disable Windows 8 compatibility for some Lenovo ThinkPads Seth Forshee
2013-04-02 5:18 ` Ben Jencks
2013-04-02 9:15 ` Aaron Lu
2013-04-02 11:23 ` Matthew Garrett
2013-04-02 13:44 ` Aaron Lu
2013-04-02 19:08 ` Matthew Garrett
2013-04-19 12:24 ` Seth Forshee
2013-04-20 22:06 ` Rafael J. Wysocki
2013-04-21 2:29 ` Seth Forshee
2013-04-21 15:46 ` Henrique de Moraes Holschuh
2013-02-13 21:09 ` Ben Jencks
2013-04-01 1:53 ` Aaron Lu
2013-04-01 13:03 ` Seth Forshee
2013-04-02 9:08 ` Aaron Lu
2013-04-02 13:00 ` Seth Forshee
2013-04-02 13:43 ` Aaron Lu
2013-04-03 7:04 ` Ben Jencks
2013-04-03 7:27 ` Aaron Lu
2013-04-03 13:45 ` Seth Forshee
2013-04-04 11:39 ` Aaron Lu
2013-04-19 3:15 ` Aaron Lu
2013-04-20 22:06 ` Rafael J. Wysocki
2013-04-21 11:07 ` Aaron Lu
2013-04-21 12:11 ` Aaron Lu
2013-04-21 21:42 ` Rafael J. Wysocki
2013-04-22 9:39 ` Aaron Lu
2013-04-22 11:51 ` Rafael J. Wysocki
2013-04-22 12:11 ` Aaron Lu
2013-04-22 13:06 ` Seth Forshee
2013-04-22 13:40 ` Aaron Lu
2013-04-22 13:56 ` Seth Forshee
2013-04-22 14:07 ` Aaron Lu
2013-04-22 15:11 ` Seth Forshee
2013-04-22 2:18 ` joeyli
2013-04-22 10:08 ` Aaron Lu
2013-04-22 12:00 ` joeyli
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