No Backlight after Suspend Sony VGN-T37GP

[Daniel Saunders]

Binary package hint: pm-utils

Ubuntu Intrepid on a Sony Vaio VGN-T37GP,
pm-utils: 1.1.2.4-1ubuntu8
Hardware: 00:02.0 VGA compatible controller: Intel Corporation 82852/855GM Integrated Graphics Device (rev 02)
Kernel: Linux vaio-laptop 2.6.27-7-generic #1 SMP Tue Nov 4 19:33:20 UTC 2008 i686 GNU/Linux

Suspend appears to work, but upon resume the LCD panel's backlight isn't turned on. Things can be seen on the screen, but it's very, very dark and the brightness controls make no difference.

The solution is to edit line 46 of /usr/lib/hal/scripts/linux/hal-system-power-suspend-linux from

HAL_PROP_POWER_MANAGEMENT_QUIRK_DPMS_SUSPEND=false
to
HAL_PROP_POWER_MANAGEMENT_QUIRK_DPMS_SUSPEND=true

This change makes the backlight turn on when resuming from suspend.

[Daniel Saunders (daniel-saunders)]

Some discussion about this bug was had: http://ubuntuforums.org/showthread.php?t=991403

[Daniel Saunders (daniel-saunders)]

I also needed to add the lines

HAL_PROP_POWER_MANAGEMENT_QUIRK_S3_BIOS=true
HAL_PROP_POWER_MANAGEMENT_QUIRK_S3_MODE=true

to the file.

This fix is also reported to work for a Sony VGN-B3VP laptop with Intrepid - http://ubuntuforums.org/showpost.php?p=6355179&postcount=13

[wirehead (wirehead)]

Just want to confirm this bug on a Sony Vaio VGN-T140P, after upgrading to Intrepid (it was working on Hardy). Adding those 3 lines fixed it for me, too (I had to add all 3). Thanks for figuring this out, Daniel... I was about to give up and go back to Hardy.

[Luke Whitmore (lwhitmore)]

Can confirm the bug on a Sony Vaio B3VP - I needed to add all three lines.

[kwrobel2005 (kay-wrobel)]

Also works for my Sony Vaio VGN-B100B using 8.10 and ver. 2.6.27-9-generic and I needed the three lines, too.

On another note, the ACPI event for unglugging/plugging the power cord has about a 45 second lag, but that's probably another bug.

[Daniel Saunders (daniel-saunders)]

@kwrobel2005 - I also get the delay with other power events. It won't be related to the particular script that we've had to edit, but it suggests that there might a more fundamental ACPI bug for our Sony laptops.

[AG Restringere (ag-restringere-deactivatedaccount)]

Can you check bug #1015297 and see if it matches your issue?

[Launchpad Janitor (janitor)]

[Expired for pm-utils (Ubuntu) because there has been no activity for 60 days.]