On 04/23/2012 05:56 PM, Daniel Vetter wrote: > On Mon, Apr 23, 2012 at 05:38:27PM +0200, Carsten Emde wrote: >> On 04/23/2012 05:22 PM, Daniel Vetter wrote: >>> On Mon, Apr 23, 2012 at 05:06:53PM +0200, Carsten Emde wrote: >>>> On 04/23/2012 04:22 PM, Daniel Vetter wrote: >>>>> On Mon, Apr 23, 2012 at 04:00:23PM +0200, Carsten Emde wrote: >>>>> [..] >>>>> The idea was to boot with kms and see whether any of these values would >>>>> restore the backlight. Writing to CTL1 should change anything in CTL2. >>>> Ah, sorry, ok. Removed the quirk again and tested the various settings: >>>> >>>> -> Initial screen: dark >>>> >>>> # intel_reg_write 0x61250 0x80000000 >>>> Value before: 0xE0000000 >>>> Value after: 0x80000000 >>>> -> Still dark >>>> >>>> # intel_reg_write 0x61250 0xa0000000 >>>> Value before: 0x80000000 >>>> Value after: 0xA0000000 >>>> -> Still dark >>>> >>>> # intel_reg_write 0x61250 0x90000000 >>>> Value before: 0xA0000000 >>>> Value after: 0x90000000 >>>> -> BACKLIGHT ON! >>>> >>>> # intel_reg_write 0x61250 0xb0000000 >>>> Value before: 0x90000000 >>>> Value after: 0xB0000000 >>>> -> Still ON. >>> >>> Neat. Let's test two more: >>> >>> # intel_reg_write 0x61250 0xd0000000 >>> # intel_reg_write 0x61250 0xc0000000 >> Here we go. >> >> -> Initial screen: dark >> >> # intel_reg_write 0x61250 0xd0000000 >> Value before: 0xE0000000 >> Value after: 0xD0000000 >> -> BACKLIGHT ON! >> >> # intel_reg_write 0x61250 0xc0000000 >> Value before: 0xD0000000 >> Value after: 0xC0000000 >> -> Dark again. > > Ok, so the polarity bit does work as advertised. But I still don't > understand how your machine works, so assuming your machine has backlight > control keys, Yes it has, but they don't have any effect. Unfortunately, I have to leave now and will be away from the lab for two days. Will continue to work on the problem when I'll be back. For the time being, I let the two conditions, your new patch and the old quirk, coexist in the code. Thanks, -Carsten.
