Re: no backlight on radeon after recent kernel "upgrade"s

[Andrew Morton <akpm@linux-foundation.org>]

On Sun, 18 Feb 2007 23:46:16 -0500 Yaroslav Halchenko <kernel@onerussian.com> wrote:

> Dear Kernel Developers,
> 
> Since the most recent successful for me kernel 2.6.19-rc6-mm1, I've
> tried few times to build more recent snapshots and now finally
> 2.6.20-mm2. In all those cases I have a sad outcome -- kernel boots but
> at some point during boot (few moments after Penguin icon in the top left
> corner appears), light turns off... I still can see something, especially
> if I light a strong flashlight at a sharp angle.
> 
> I've enabled back-light support and lcd support for those unsuccessful
> kernels (with all backlight support features disabled kernel boots
> ok and backlight shines as bright as always)
> 
> All my changes of values for files under
> /sys/class/backlight/radeonbl0
> had no impact on the screen. Also I had no files under /sys/class/lcd.
> 
> Running 
> radeontool light off
> caused complete turning off of LCD - I could not see
> anything anymore.
> 
> sony's spictl -b had no effect as well.
> 
> Config can be found at
> http://www.onerussian.com/Linux/bugs/nobacklight.1/config-2.6.20-mm2
> lshw
> http://www.onerussian.com/Linux/bugs/nobacklight.1/lshw
> other details are available from
> http://www.onerussian.com/Linux/bugs/nobacklight.1/
> 
> Could you please advise?

(cc's added)

Is 2.6.20 broken?  I assume the latest 2.6.20-gitN snapshot are failing..