** Summary changed: - display brightness is not saved + display brightness is setup to 100% after power up
** Description changed: - I have NX7400 laptop. Afer power up display backlight is didn't saved - and light at 100% light. I detected that problem is in acpi kernel - driver video. I use ubuntu 8.10 with kernel 2.6.27-7-generic. This is a - regression bug, because in previous version ubuntu 8.04LTS display - backlight works ok. + I have NX7400 laptop. Afer power up display backlight is always set to + 100% light, independent of brightness settings in previous session. I + detected that problem is in acpi kernel driver video.ko and gnome-power- + manager. I use ubuntu 8.10 with kernel 2.6.27-7-generic on 64-bit + platform. This is a regression bug, because in previous version ubuntu + 8.04LTS display backlight works ok. + + Aditional comments: + + I detected that acpi/video.ko kernel 2.6.24 driver in ubuntu 8.04 + didn't work and backlight was controlled only by ACPI bios, because + /proc/bus/acpi/video/*/backlights always return that backlight is not + supported. In kernel 2.6.27 driver return correct backlight values: + + cat /proc/acpi/video/C085/C144/brightness + levels: 100 51 30 37 44 51 58 65 72 79 86 93 100 + current: 65 + + New video driver trying to get current backlight level from ACPI BQI + object but it is optional ACPI function. When ACPI does not support BQI + object driver will set back-light to maximum value. Pls. see code + video.c bellow: + + if (device->cap._BQC) + device->backlight->props.brightness = + acpi_video_get_brightness(device->backlight); + else + device->backlight->props.brightness = + device->backlight->props.max_brightness; + backlight_update_status(device->backlight); - This is lspci dump: + When ACPI BQI is not supported video.ko or gnome-power-manager should save and restore current backlight value from config file. - 00:00.0 Host bridge: Intel Corporation Mobile 945GM/PM/GMS, 943/940GML and 945GT Express Memory Controller Hub (rev 03) - 00:02.0 VGA compatible controller: Intel Corporation Mobile 945GM/GMS, 943/940GML Express Integrated Graphics Controller (rev 03) - 00:02.1 Display controller: Intel Corporation Mobile 945GM/GMS/GME, 943/940GML Express Integrated Graphics Controller (rev 03) - 00:1b.0 Audio device: Intel Corporation 82801G (ICH7 Family) High Definition Audio Controller (rev 01) - 00:1c.0 PCI bridge: Intel Corporation 82801G (ICH7 Family) PCI Express Port 1 (rev 01) - 00:1c.1 PCI bridge: Intel Corporation 82801G (ICH7 Family) PCI Express Port 2 (rev 01) - 00:1c.3 PCI bridge: Intel Corporation 82801G (ICH7 Family) PCI Express Port 4 (rev 01) - 00:1d.0 USB Controller: Intel Corporation 82801G (ICH7 Family) USB UHCI Controller #1 (rev 01) - 00:1d.1 USB Controller: Intel Corporation 82801G (ICH7 Family) USB UHCI Controller #2 (rev 01) - 00:1d.2 USB Controller: Intel Corporation 82801G (ICH7 Family) USB UHCI Controller #3 (rev 01) - 00:1d.3 USB Controller: Intel Corporation 82801G (ICH7 Family) USB UHCI Controller #4 (rev 01) - 00:1d.7 USB Controller: Intel Corporation 82801G (ICH7 Family) USB2 EHCI Controller (rev 01) - 00:1e.0 PCI bridge: Intel Corporation 82801 Mobile PCI Bridge (rev e1) - 00:1f.0 ISA bridge: Intel Corporation 82801GBM (ICH7-M) LPC Interface Bridge (rev 01) - 00:1f.1 IDE interface: Intel Corporation 82801G (ICH7 Family) IDE Controller (rev 01) - 00:1f.2 SATA controller: Intel Corporation 82801GBM/GHM (ICH7 Family) SATA AHCI Controller (rev 01) - 02:06.0 CardBus bridge: Texas Instruments PCIxx12 Cardbus Controller - 02:06.1 FireWire (IEEE 1394): Texas Instruments PCIxx12 OHCI Compliant IEEE 1394 Host Controller - 02:0e.0 Ethernet controller: Broadcom Corporation BCM4401-B0 100Base-TX (rev 02) - 10:00.0 Network controller: Intel Corporation PRO/Wireless 3945ABG [Golan] Network Connection (rev 02) + Workaround: + + Currently I workaround this problem by change kernel driver video.ko to + set 50% backlight when BQI object is not found (Pls see patch bellow). + And edit gnome-power-manager settings by run gconf-editor and changed + following configuration values in /apps/gnome-power/manager/backlight by + changing keys: + + brightness_ac = 50 + brightness_battery = 30 + brightness_dim_battery = 30 + + but it is obvious workaround. ** Attachment added: "acpi video backlight patch" http://launchpadlibrarian.net/19190581/kernel-2.6.27-acpi-video.patch ** Description changed: I have NX7400 laptop. Afer power up display backlight is always set to 100% light, independent of brightness settings in previous session. I detected that problem is in acpi kernel driver video.ko and gnome-power- manager. I use ubuntu 8.10 with kernel 2.6.27-7-generic on 64-bit platform. This is a regression bug, because in previous version ubuntu 8.04LTS display backlight works ok. Aditional comments: I detected that acpi/video.ko kernel 2.6.24 driver in ubuntu 8.04 didn't work and backlight was controlled only by ACPI bios, because /proc/bus/acpi/video/*/backlights always return that backlight is not supported. In kernel 2.6.27 driver return correct backlight values: cat /proc/acpi/video/C085/C144/brightness levels: 100 51 30 37 44 51 58 65 72 79 86 93 100 current: 65 New video driver trying to get current backlight level from ACPI BQI object but it is optional ACPI function. When ACPI does not support BQI object driver will set back-light to maximum value. Pls. see code video.c bellow: if (device->cap._BQC) device->backlight->props.brightness = acpi_video_get_brightness(device->backlight); else device->backlight->props.brightness = device->backlight->props.max_brightness; backlight_update_status(device->backlight); When ACPI BQI is not supported video.ko or gnome-power-manager should save and restore current backlight value from config file. Workaround: Currently I workaround this problem by change kernel driver video.ko to - set 50% backlight when BQI object is not found (Pls see patch bellow). - And edit gnome-power-manager settings by run gconf-editor and changed + set 50% backlight when BQI object is not found (Pls see patch bellow). I + alse changed gnome-power-manager settings by run gconf-editor and set following configuration values in /apps/gnome-power/manager/backlight by - changing keys: + changing keys values to: brightness_ac = 50 brightness_battery = 30 brightness_dim_battery = 30 but it is obvious workaround. ** Changed in: gnome-power-manager (Ubuntu) Sourcepackagename: None => gnome-power-manager -- display brightness is setup to 100% after power up https://bugs.launchpad.net/bugs/291742 You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
