I'm seeing an odd issue with KDE and screen backlight control. I'm running Thinkpad T60, with KDE 4.7 (from updates) and unfortunately the backlight control does not work. Pressing Fn+Home/Fn+End does not seem to have any effect. I normally have to tweak hotkey mask to something like 0xffffff in order to have the proper key events appear, and it does work but only in Gnome and Xfce. Before anyone suggests reinstalling bash, I've already done it (otherwise it wouldn't work in Xfce).
Looking at the logs: - kded debugs: kded(2495) PowerDevil::BackendLoader::loadBackend: Loading UPower backend... kded(2495) PowerDevil::BackendLoader::loadBackend: Success! kded(2495) KDEDPowerDevil::init: Backend loaded, loading core kded(2495) PowerDevil::Core::loadCore: Core loaded, initializing backend kded(2495) PowerDevilUPowerBackend::brightness: Screen brightness: 0 <---- why is current brightness 0? kded(2495) PowerDevilUPowerBackend::init: current screen brightness: 0 kded(2495) PowerDevilUPowerBackend::init: Can suspend kded(2495) PowerDevilUPowerBackend::init: Can hibernate kded(2495) PowerDevil::Core::onBackendReady: Backend is ready, KDE Power Management system initialized
- messages - nothing about backlight helper being activated - .xsession-errors - nothing related
Since it does not work with 4.7 from updates, I updated to 4.8 from kde48 repo. Unfortunately, with similar results.
As a last resort I checked with KDE live spin, and amazingly, backlight control works. So something between the current version of packages and the one from live KDE spin, things got broken.
Correct me if I'm wrong, but looking at the code, I see that in order to control the backlight, there's a helper program (/usr/libexec/kde4/backlighthelper) which starts through dbus activation, and exposes brigthness, setbrigthness methods. I take that once started the demon should remain running at lest for some time. Now in KDE spin, that happens to be the case, I can clearly see backlighthelper process listed in ps output (there are also logs in messages, that activation of backlighthelper was successful). However, right now, no such log is to be found, as if for some reason backlight helper does not get started.
Any ideas on how to proceed with debugging this?
Thanks, -- Maciek Borzecki
Dne Ne 4. března 2012 13:58:36, Maciek Borzecki napsal(a):
I'm seeing an odd issue with KDE and screen backlight control. I'm running Thinkpad T60, with KDE 4.7 (from updates) and unfortunately the backlight control does not work. Pressing Fn+Home/Fn+End does not seem to have any effect. I normally have to tweak hotkey mask to something like 0xffffff in order to have the proper key events appear, and it does work but only in Gnome and Xfce. Before anyone suggests reinstalling bash, I've already done it (otherwise it wouldn't work in Xfce).
Looking at the logs:
- kded debugs:
kded(2495) PowerDevil::BackendLoader::loadBackend: Loading UPower backend... kded(2495) PowerDevil::BackendLoader::loadBackend: Success! kded(2495) KDEDPowerDevil::init: Backend loaded, loading core kded(2495) PowerDevil::Core::loadCore: Core loaded, initializing backend kded(2495) PowerDevilUPowerBackend::brightness: Screen brightness: 0 <---- why is current brightness 0? kded(2495) PowerDevilUPowerBackend::init: current screen brightness: 0 kded(2495) PowerDevilUPowerBackend::init: Can suspend kded(2495) PowerDevilUPowerBackend::init: Can hibernate kded(2495) PowerDevil::Core::onBackendReady: Backend is ready, KDE Power Management system initialized
- messages - nothing about backlight helper being activated
- .xsession-errors - nothing related
Since it does not work with 4.7 from updates, I updated to 4.8 from kde48 repo. Unfortunately, with similar results.
As a last resort I checked with KDE live spin, and amazingly, backlight control works. So something between the current version of packages and the one from live KDE spin, things got broken.
Correct me if I'm wrong, but looking at the code, I see that in order to control the backlight, there's a helper program (/usr/libexec/kde4/backlighthelper) which starts through dbus activation, and exposes brigthness, setbrigthness methods. I take that once started the demon should remain running at lest for some time. Now in KDE spin, that happens to be the case, I can clearly see backlighthelper process listed in ps output (there are also logs in messages, that activation of backlighthelper was successful). However, right now, no such log is to be found, as if for some reason backlight helper does not get started.
Any ideas on how to proceed with debugging this?
Thanks,
Maciek Borzecki _______________________________________________ kde mailing list kde@lists.fedoraproject.org https://admin.fedoraproject.org/mailman/listinfo/kde New to KDE4? - get help from http://userbase.kde.org
Please post the result from "ls /sys/class/backlight/" on both systems
Problem solved, or at least I found a working workaround. Switching to acpi_backlight=vendor makes things better. I can control brigthness by using Fn keys, and the OSD appears when doing so.
Anyway the contents of backlight (avter using acpi_backlight=vendor) $ ls -l /sys/class/backlight total 0 lrwxrwxrwx. 1 root root 0 Mar 5 21:00 thinkpad_screen -> ../../devices/virtual/backlight/thinkpad_screen
Before the change, standard ACPI interface was there (acpi_backlight=native, the default I guess), and it worked doing echo [0-9] > brigthness.
Judging by kded/radeon code, it seems that powerdevil will use xrandr brightness control when available (i.e. availability is reported by querying Backlight property). Although setting 'Backlight' is not supported by open source radeon driver, the check if the interface exists succeeds. That's why it ended up trying to use xranrd which does not work. The question is why the check even succeeded.
Funny though, xfce/gnome do not seem to ever use xrandr interface, and always use /sys.
-- Maciek Borzecki
On Mon, Mar 5, 2012 at 1:03 PM, Lukáš Tinkl ltinkl@redhat.com wrote:
Dne Ne 4. března 2012 13:58:36, Maciek Borzecki napsal(a):
I'm seeing an odd issue with KDE and screen backlight control. I'm running Thinkpad T60, with KDE 4.7 (from updates) and unfortunately the backlight control does not work. Pressing Fn+Home/Fn+End does not seem to have any effect. I normally have to tweak hotkey mask to something like 0xffffff in order to have the proper key events appear, and it does work but only in Gnome and Xfce. Before anyone suggests reinstalling bash, I've already done it (otherwise it wouldn't work in Xfce).
Looking at the logs:
- kded debugs:
kded(2495) PowerDevil::BackendLoader::loadBackend: Loading UPower backend... kded(2495) PowerDevil::BackendLoader::loadBackend: Success! kded(2495) KDEDPowerDevil::init: Backend loaded, loading core kded(2495) PowerDevil::Core::loadCore: Core loaded, initializing backend kded(2495) PowerDevilUPowerBackend::brightness: Screen brightness: 0 <---- why is current brightness 0? kded(2495) PowerDevilUPowerBackend::init: current screen brightness: 0 kded(2495) PowerDevilUPowerBackend::init: Can suspend kded(2495) PowerDevilUPowerBackend::init: Can hibernate kded(2495) PowerDevil::Core::onBackendReady: Backend is ready, KDE Power Management system initialized
- messages - nothing about backlight helper being activated
- .xsession-errors - nothing related
Since it does not work with 4.7 from updates, I updated to 4.8 from kde48 repo. Unfortunately, with similar results.
As a last resort I checked with KDE live spin, and amazingly, backlight control works. So something between the current version of packages and the one from live KDE spin, things got broken.
Correct me if I'm wrong, but looking at the code, I see that in order to control the backlight, there's a helper program (/usr/libexec/kde4/backlighthelper) which starts through dbus activation, and exposes brigthness, setbrigthness methods. I take that once started the demon should remain running at lest for some time. Now in KDE spin, that happens to be the case, I can clearly see backlighthelper process listed in ps output (there are also logs in messages, that activation of backlighthelper was successful). However, right now, no such log is to be found, as if for some reason backlight helper does not get started.
Any ideas on how to proceed with debugging this?
Thanks,
Maciek Borzecki _______________________________________________ kde mailing list kde@lists.fedoraproject.org https://admin.fedoraproject.org/mailman/listinfo/kde New to KDE4? - get help from http://userbase.kde.org
Please post the result from "ls /sys/class/backlight/" on both systems
Lukáš Tinkl ltinkl@redhat.com Software Engineer - Base Operating Systems Brno KDE developer lukas@kde.org Red Hat Inc. http://cz.redhat.com _______________________________________________ kde mailing list kde@lists.fedoraproject.org https://admin.fedoraproject.org/mailman/listinfo/kde New to KDE4? - get help from http://userbase.kde.org