From mboxrd@z Thu Jan 1 00:00:00 1970 From: Troy Schultz Subject: Re: hp xt1260; upgraded bios to 1.05, now no backlight w/batteries Date: 06 Mar 2003 06:53:57 -0500 Sender: acpi-devel-admin-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org Message-ID: <1046951637.1634.3.camel@p2710> References: <200303051956.h25Ju2N04777@p2.parker.boston.ma.us> Mime-Version: 1.0 Content-Type: text/plain Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <200303051956.h25Ju2N04777-paYRYfI9b/YMuHHiPFXXZ1fOaUvyCJUZ@public.gmane.org> Errors-To: acpi-devel-admin-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org List-Help: List-Post: List-Subscribe: , List-Unsubscribe: , List-Archive: To: Brad Parker Cc: ACPI Development - Sourceforge List-Id: linux-acpi@vger.kernel.org On Wed, 2003-03-05 at 14:56, Brad Parker wrote: > 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 ------------------------------------------------------- This SF.net email is sponsored by: Etnus, makers of TotalView, The debugger for complex code. Debugging C/C++ programs can leave you feeling lost and disoriented. TotalView can help you find your way. Available on major UNIX and Linux platforms. Try it free. www.etnus.com