From mboxrd@z Thu Jan 1 00:00:00 1970 From: Matthew Garrett Date: Tue, 13 Mar 2012 12:47:38 +0000 Subject: Re: [PATCH] Added backlight driver for Acer Aspire 4736 Message-Id: <20120313124738.GB10822@srcf.ucam.org> List-Id: References: <1331608337.2267.67.camel@debian.Gayathri> <20120312175130.GA18002@srcf.ucam.org> <1331640592.3485.50.camel@debian.Gayathri> In-Reply-To: <1331640592.3485.50.camel@debian.Gayathri> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: Pradeep Subrahmanion Cc: rpurdie@rpsys.net, FlorianSchandinat@gmx.de, akpm@linux-foundation.org, linux-fbdev@vger.kernel.org, linux-kernel@vger.kernel.org On Tue, Mar 13, 2012 at 08:09:52AM -0400, Pradeep Subrahmanion wrote: > Before taking this approach , I had a look at the WMI interface.But I found from acer-acpi site that , the 4730 series > is using new WMI interface which needs to be reverse engineered. > As far as acpi interface is concerned , by default it is not at all causing any change in brightness. > When 'acpi_osi=Linux' was added to the boot grub config , the brightness control with hot key started to work . > But it was not changing to correct values. Increasing brightness after maximum level gives blank screen. That page was last updated in 2009. Have you tried the current acer-wmi code? You'd probably need to pass backlight=vendor if there's a non-working ACPI interface. When you say the ACPI interface doesn't work, what do you mean? Have you tried using the /sys/class/backlight interface directly? -- Matthew Garrett | mjg59@srcf.ucam.org