Re: hp xt1260; upgraded bios to 1.05, now no backlight w/batteries

[Troy Schultz <tschultz-zzOxFVvAfJPQT0dZR+AlfA@public.gmane.org>]

On Wed, 2003-03-05 at 14:56, Brad Parker wrote:

<snip>


> I recently upgraded the bios to "v1.05" because the HP web site said
> it had ACPI fixes.
> 
> Once I did that the backlight stopped working when the ac power was not connected.
> 
> Oddly, this seems to be caused by running linux.  
> 
> If I boot the bios upgrade disk and flash the bios, the problem goes
> away.  Everything works as expected.
> 
> I then run linux (2.4.21-pre3-acpi-20030125-swsusp18).  It boots and
> works fine.  I poweroff and reboot and the problem reoccurs.  Several
> seconds after the bios comes up, before grub, the backlight shuts off.
> Pressing the lid button restores the light for a few seconds.  If I
> plug in the ac and press the lid button is comes back on and stays on.
> 
> This linux has a "fixed" DSDT table.  The changes are very minor (one
> missing global, one bad length, several bad access types).  I
> originally did this because I could not see the battery or power
> info. With the fixes the battery and power work as expected.
> 
> If I remove the battery and press the reset button the problem stays.  It makes
> me wonder if the DSDT 'code' is wacking some persistent memory inside the
> unit...  is that possible?
> 
> Should I try using the bios version of the DSDT?

Yes, most likely the DSDT was changed in the new BIOS.  I would suggest
you try the new BIOS's DSDT first, and then if you have problems you
will have to grab the new DSDT and make changes if necessary.

Best Regards
-- 
Troy Schultz <tschultz-zzOxFVvAfJPQT0dZR+AlfA@public.gmane.org>



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