I tried giving acpi_backlight = vendor . In that case hot key for brightness control is working. But i think , it is not calculating the correct value for brightness because increasing brightness after maximum level gives blank screen . I also had tried 'acpi_backlight = acer_wmi' as the boot parameter earlier . In that case , the driver cannot find any acpi_wmi device (showed error while booting). By ' ACPI interface' , I mean 'acpi_video0' inside the /sys/class/backlight. I havn't tried the /sys/class/backlight interface directly . I will try that also. Thanks , Pradeep Subrahmanion. On Tue, Mar 13, 2012 at 6:17 PM, Matthew Garrett <mjg@xxxxxxxxxx> wrote: > > 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@xxxxxxxxxxxxx -- To unsubscribe from this list: send the line "unsubscribe linux-fbdev" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
