From: Seth Forshee <seth.forshee@canonical.com>
To: Matthew Garrett <mjg59@srcf.ucam.org>,
Corentin Chary <corentin.chary@gmail.com>
Cc: platform-driver-x86@vger.kernel.org,
linux-kernel@vger.kernel.org,
linux acpi <linux-acpi@vger.kernel.org>,
Len Brown <len.brown@intel.com>
Subject: Re: [PATCH] samsung-laptop: unregister ACPI video module for some well known laptops
Date: Fri, 6 Apr 2012 09:34:55 -0500 [thread overview]
Message-ID: <20120406143455.GC8666@thinkpad-t410> (raw)
In-Reply-To: <CAHR064hBVJjmEd=GeGuG-xTg5ONfJTxwqzP88=JABaXFrfiehA@mail.gmail.com>
On Fri, Apr 06, 2012 at 11:42:18AM +0200, Corentin Chary wrote:
> On Tue, Mar 27, 2012 at 1:21 PM, Matthew Garrett <mjg59@srcf.ucam.org> wrote:
> > On Tue, Mar 27, 2012 at 11:11:18AM +0200, Corentin Chary wrote:
> >> Matthew, is this one ok ? I really hope this patch can go in 3.4 so we
> >> don't introduce a regression for old laptops.
> >
> > Yes, I've got this now.
> >
> > Thanks,
>
>
> A user just found a DSDT which is broken by this way of doing things
> (this is not really a regression since it was also broken before).
>
> _BCL contains a wierd "Or (VDRV, 0x02, VDRV)".
> So if you call _BLC once (video.ko will), it set a flag that affect
> the behavior of all backlight related stuff, and it breaks
> samsung-laptop's backlight even if samsung-laptop unload the acpi
> backlight.
> Using acpi_backlight=vendor solves that since it prevents the module
> from being loaded. My previous patch also fix that since it use
> acpi_backlight= mechanism.
>
> Do you think using acpi_backlight=vendor is a good enought solution
> here ? Should we use my first patch instead ?
I've recently noticed another problem with using acpi_video_unregister()
to disable known broken backlights -- another module might call
acpi_video_register() and make it reappear. i915 does this, so when I
EFI boot the MacBook Pro 8,2 the acpi backlights reappear (under a BIOS
compatible boot the Intel GPU doesn't show up on the bus).
So Corentin's solution does seem like a better way to go, or else
something similar that forces the ACPI video driver to behave as with
acpi_video=vendor.
Seth
next prev parent reply other threads:[~2012-04-06 14:35 UTC|newest]
Thread overview: 23+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <1332233594-13099-1-git-send-email-corentin.chary@gmail.com>
2012-03-20 8:53 ` [PATCH 01/14] ACPI / Video: blacklist some samsung laptops Corentin Chary
2012-03-20 16:05 ` Matthew Garrett
2012-03-20 16:28 ` Corentin Chary
2012-03-20 16:30 ` Matthew Garrett
2012-03-22 13:08 ` [PATCH] samsung-laptop: unregister ACPI video module for some well known laptops Corentin Chary
2012-03-27 9:11 ` Corentin Chary
2012-03-27 11:21 ` Matthew Garrett
2012-04-06 9:42 ` Corentin Chary
2012-04-06 14:34 ` Seth Forshee [this message]
2012-04-17 8:31 ` Corentin Chary
2012-03-20 8:53 ` [PATCH 02/14] asus-nb-wmi: ignore useless keys Corentin Chary
2012-03-20 8:53 ` [PATCH 03/14] eeepc-wmi: add extra keymaps for EP121 Corentin Chary
2012-03-20 8:53 ` [PATCH 04/14] asus-wmi: on/off bit is not set when reading the value Corentin Chary
2012-03-20 8:53 ` [PATCH 05/14] drivers, samsung-laptop: fix initialization of sabi_data in sabi_set_commandb Corentin Chary
2012-03-20 8:53 ` [PATCH 06/14] drivers, samsung-laptop: fix usage of isalnum Corentin Chary
2012-03-20 8:53 ` [PATCH 07/14] samsung-laptop: cleanup return type: mode_t vs umode_t Corentin Chary
2012-03-20 8:53 ` [PATCH 08/14] asus-wmi: add scalar board brightness adj. support Corentin Chary
2012-03-20 8:53 ` [PATCH 09/14] asus-wmi: store backlight power status for AIO machine Corentin Chary
2012-03-20 8:53 ` [PATCH 10/14] asus-wmi: move WAPF variable into quirks_entry Corentin Chary
2012-03-20 8:53 ` [PATCH 11/14] asus-nb-wmi: set panel_power correctly Corentin Chary
2012-03-20 8:53 ` [PATCH 12/14] eeepc-wmi: refine quirks handling Corentin Chary
2012-03-20 8:53 ` [PATCH 13/14] eeepc-wmi: split et2012 specific hacks Corentin Chary
2012-03-20 8:53 ` [PATCH 14/14] asus-wmi: don't update power and brightness when using scalar Corentin Chary
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