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From: Matthew Garrett <mjg59@srcf.ucam.org>
To: Alan Stern <stern@rowland.harvard.edu>
Cc: Zhang Rui <rui.zhang@intel.com>,
	"linux-acpi@vger.kernel.org" <linux-acpi@vger.kernel.org>
Subject: Re: ACPI_VIDEO and BACKLIGHT_CLASS_DEVICE
Date: Fri, 12 Nov 2010 03:46:15 +0000	[thread overview]
Message-ID: <20101112034614.GB7407@srcf.ucam.org> (raw)
In-Reply-To: <Pine.LNX.4.44L0.1011112156570.2098-100000@netrider.rowland.org>

On Thu, Nov 11, 2010 at 10:00:03PM -0500, Alan Stern wrote:

> But my computer doesn't have an LCD display.  It's a desktop, not a
> laptop.  So why do I need BACKLIGHT_CLASS_DEVICE to be enabled?

Well, in the near future ddc-ci will be hooked up and you'll have 
backlight control over VGA if your monitor supports it, so even if we 
fix this up now you'll just end up getting it back in the near future 
because we can't tell that at build-time...

> Are you saying I don't need ACPI_VIDEO if the machine doesn't have an
> integrated LCD display?  That doesn't agree with the Kconfig help
> message.

But to that, yes. The only reason to use ACPI_VIDEO is to get EDID from 
firmware (which isn't relevant on desktops) or to control backlights. 
Every other theoretical feature it has is useless in the real world.

-- 
Matthew Garrett | mjg59@srcf.ucam.org

  reply	other threads:[~2010-11-12  3:46 UTC|newest]

Thread overview: 7+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2010-11-10 22:02 ACPI_VIDEO and BACKLIGHT_CLASS_DEVICE Alan Stern
2010-11-12  2:07 ` Zhang Rui
2010-11-12  3:00   ` Alan Stern
2010-11-12  3:46     ` Matthew Garrett [this message]
2010-11-12 21:26       ` Alan Stern
2010-11-12 21:36         ` Matthew Garrett
2010-11-15  0:33           ` Zhang Rui

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