On Tue, 2012-03-13 at 13:34 +0000, Matthew Garrett wrote: > On Tue, Mar 13, 2012 at 06:56:16PM +0530, Pradeep Subrahmanion wrote: > > 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 . > > Which backlight device appears then? > 'intel_backlight' appears when i gave option acpi_backlight = vendor. Writing to /sys/class/backlight/intel_backlight/brightness does not cause any change in brightness. > > 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. > > So writing values into /sys/class/backlight/acpi_video0/brightness does > nothing? No change in value when writing to /sys/class/backlight/acpi_video0/brightness. Another thing is that when i did boot with acpi_backlight = 'acer_wmi' , in new kernel (3.3.0-rc7) , it shows following messages , [ 8.350825] wmi: Mapper loaded [ 10.363975] acer_wmi: Acer Laptop ACPI-WMI Extras [ 10.396186] acer_wmi: Function bitmap for Communication Device: 0x91 [ 10.396385] acer_wmi: Brightness must be controlled by generic video driver Also there was no interface inside /sys/class/backlight for acer_wmi. I also tried writing directly to Embedded controller register .But no change. ---- Thanks , Pradeep Subrahmanion -- 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
