[Bug 554563] New: Brightness is increased when set too low
http://bugzilla.novell.com/show_bug.cgi?id=554563 Summary: Brightness is increased when set too low Classification: openSUSE Product: openSUSE 11.2 Version: RC 2 Platform: x86-64 OS/Version: openSUSE 11.2 Status: NEW Severity: Normal Priority: P5 - None Component: Kernel AssignedTo: kernel-maintainers@forge.provo.novell.com ReportedBy: poletti.marco@gmail.com QAContact: qa@suse.de Found By: --- User-Agent: Mozilla/5.0 (X11; U; Linux x86_64; it; rv:1.9.1.4) Gecko/20091016 SUSE/3.5.4-1.1.2 Firefox/3.5.4 GTB5 Brightness control works on my Gateway Tablet PC, but only if you set brightness >=13%. If you set it lower, say 12%, the brightness appears as you set ~30% (brighter than if you set 13%). No matter how much lower you set it, you always get the same level. I explain better with a table: you set | you get --------+-------- 0% | ~30% 5% | ~30% 12% | ~30% --------+-------- 13% | 13% 50% | 50% 100% | 100% If this was done to prevent user from choosing 0%, you should set the internal brightness to 13% when user selects something <13%. In this case, I would also suggest to lower this bound, to say 5%, to allow extreme power saving on laptops. Reproducible: Always Steps to Reproduce: 1. 2. 3. -- Configure bugmail: http://bugzilla.novell.com/userprefs.cgi?tab=email ------- You are receiving this mail because: ------- You are on the CC list for the bug.
http://bugzilla.novell.com/show_bug.cgi?id=554563 http://bugzilla.novell.com/show_bug.cgi?id=554563#c Jeff Mahoney <jeffm@novell.com> changed: What |Removed |Added ---------------------------------------------------------------------------- Priority|P5 - None |P3 - Medium CC| |jeffm@novell.com AssignedTo|kernel-maintainers@forge.pr |trenn@novell.com |ovo.novell.com | -- Configure bugmail: http://bugzilla.novell.com/userprefs.cgi?tab=email ------- You are receiving this mail because: ------- You are on the CC list for the bug.
http://bugzilla.novell.com/show_bug.cgi?id=554563 http://bugzilla.novell.com/show_bug.cgi?id=554563#c1 Thomas Renninger <trenn@novell.com> changed: What |Removed |Added ---------------------------------------------------------------------------- Priority|P3 - Medium |P4 - Low Status|NEW |ASSIGNED Severity|Normal |Minor --- Comment #1 from Thomas Renninger <trenn@novell.com> 2009-11-27 14:31:17 UTC --- This even might be a BIOS issue. Could you describe which driver (video.ko or a laptop specific is responsible for doing the switching). What kind of machine is that? How much and which brightness levels do you have? find /sys/ |grep backlight should help you to find out some more things... -- Configure bugmail: http://bugzilla.novell.com/userprefs.cgi?tab=email ------- You are receiving this mail because: ------- You are on the CC list for the bug.
http://bugzilla.novell.com/show_bug.cgi?id=554563 http://bugzilla.novell.com/show_bug.cgi?id=554563#c Thomas Renninger <trenn@novell.com> changed: What |Removed |Added ---------------------------------------------------------------------------- Status|ASSIGNED |NEEDINFO Info Provider| |poletti.marco@gmail.com -- Configure bugmail: http://bugzilla.novell.com/userprefs.cgi?tab=email ------- You are receiving this mail because: ------- You are on the CC list for the bug.
http://bugzilla.novell.com/show_bug.cgi?id=554563 http://bugzilla.novell.com/show_bug.cgi?id=554563#c2 Marco Poletti <poletti.marco@gmail.com> changed: What |Removed |Added ---------------------------------------------------------------------------- Status|NEEDINFO |ASSIGNED Info Provider|poletti.marco@gmail.com | --- Comment #2 from Marco Poletti <poletti.marco@gmail.com> 2009-11-27 19:37:51 CET --- I got it to work using "native", "combination" and "legacy" as BACKLIGHT_CONTROL: works (range 0..50001) : xrandr --output LVDS --set BACKLIGHT_CONTROL native works (range 0..25000) : xrandr --output LVDS --set BACKLIGHT_CONTROL combination works (range 0..255): xrandr --output LVDS --set BACKLIGHT_CONTROL legacy doesn't work (range 0..8, default) : xrandr --output LVDS --set BACKLIGHT_CONTROL kernel I set the brightness via "xbacklight -set [value]". If I remember correctly, this worked fine some months ago (11.2 M7 or M8) on this computer.
Could you describe which driver (video.ko or a laptop specific is responsible for doing the switching).
How can I check this?
What kind of machine is that?
It's a Gateway Tablet PC, model C143-X.
find /sys/ |grep backlight should help you to find out some more things...
It outputs: /sys/devices/virtual/backlight /sys/devices/virtual/backlight/acpi_video0 /sys/devices/virtual/backlight/acpi_video0/uevent /sys/devices/virtual/backlight/acpi_video0/subsystem /sys/devices/virtual/backlight/acpi_video0/bl_power /sys/devices/virtual/backlight/acpi_video0/brightness /sys/devices/virtual/backlight/acpi_video0/actual_brightness /sys/devices/virtual/backlight/acpi_video0/max_brightness /sys/devices/virtual/backlight/acpi_video0/power /sys/devices/virtual/backlight/acpi_video0/power/wakeup /sys/devices/virtual/backlight/acpi_video0/device /sys/class/backlight /sys/class/backlight/acpi_video0 -- Configure bugmail: http://bugzilla.novell.com/userprefs.cgi?tab=email ------- You are receiving this mail because: ------- You are on the CC list for the bug.
http://bugzilla.novell.com/show_bug.cgi?id=554563 http://bugzilla.novell.com/show_bug.cgi?id=554563#c3 Thomas Renninger <trenn@novell.com> changed: What |Removed |Added ---------------------------------------------------------------------------- Status|ASSIGNED |NEEDINFO Info Provider| |poletti.marco@gmail.com --- Comment #3 from Thomas Renninger <trenn@novell.com> 2009-11-27 20:32:11 UTC --- That is exactly the info I asked for thanks. video.ko is used for brightness switching. Can you also attach acpidump, please. I expect this is a BIOS bug. As we are not in closer contact with Gateway AFAIK (this machine is not a SUSE/Novell certified one?), I doubt we can do much. The bug also isn't sever and even can already be workarounded... -- Configure bugmail: http://bugzilla.novell.com/userprefs.cgi?tab=email ------- You are receiving this mail because: ------- You are on the CC list for the bug.
http://bugzilla.novell.com/show_bug.cgi?id=554563 http://bugzilla.novell.com/show_bug.cgi?id=554563#c4 Marco Poletti <poletti.marco@gmail.com> changed: What |Removed |Added ---------------------------------------------------------------------------- Status|NEEDINFO |ASSIGNED Info Provider|poletti.marco@gmail.com | --- Comment #4 from Marco Poletti <poletti.marco@gmail.com> 2009-11-27 21:44:58 CET --- Created an attachment (id=329845) --> (http://bugzilla.novell.com/attachment.cgi?id=329845) acpidump result I attach the output of "acpidump". My tablet shipped with MS Vista only, I really don't think it's SUSE-certified. If this is a BIOS bug, can we add a workaround like: if (computer.model == "C143-X") setBrightnessControl("native"); somewhere, maybe in the kernel? I can workaround this using the xrandr commands I said in the previous comment, but I don't know how to do this during the boot process (so that KDE's powerdevil uses the "native" brightness control instead of "kernel"). -- Configure bugmail: http://bugzilla.novell.com/userprefs.cgi?tab=email ------- You are receiving this mail because: ------- You are on the CC list for the bug.
http://bugzilla.novell.com/show_bug.cgi?id=554563 http://bugzilla.novell.com/show_bug.cgi?id=554563#c5 --- Comment #5 from Thomas Renninger <trenn@novell.com> 2009-11-27 21:17:52 UTC --- The right place to add such a hack would be in hal, here: /usr/share/hal/fdi/information Not sure if such a thing with brightness is possible, you might want to grep through the files for an example. -- Configure bugmail: http://bugzilla.novell.com/userprefs.cgi?tab=email ------- You are receiving this mail because: ------- You are on the CC list for the bug.
http://bugzilla.novell.com/show_bug.cgi?id=554563 http://bugzilla.novell.com/show_bug.cgi?id=554563#c6 --- Comment #6 from Marco Poletti <poletti.marco@gmail.com> 2009-11-28 07:28:59 CET --- I looked in that folder, but didn't find anything related to brightness control. There are some brightness-keys related hacks, however. Does this mean we cannot add a hack if we don't modify the program who reads those files? Or can we add an hack however? -- Configure bugmail: http://bugzilla.novell.com/userprefs.cgi?tab=email ------- You are receiving this mail because: ------- You are on the CC list for the bug.
http://bugzilla.novell.com/show_bug.cgi?id=554563 http://bugzilla.novell.com/show_bug.cgi?id=554563#c7 Thomas Renninger <trenn@novell.com> changed: What |Removed |Added ---------------------------------------------------------------------------- Status|ASSIGNED |RESOLVED CC| |rui.zhang@intel.com Resolution| |WONTFIX --- Comment #7 from Thomas Renninger <trenn@novell.com> 2009-11-29 13:33:22 UTC --- Rui: A feeling tells me that we cannot do much about it, but you might want to have a look at the acpidump, so that you are aware of yet another busted ACPI brightness implementation... About the hack: You might want to find an X-related entry point calling this. Or depending on your desktop, possibly you can add this to the kpowersave/powerdevil/gnome-power-management startup script? I close this as a BIOS bug -> won't fix. If a BIOS upgrade fixes this, please let us and other know about it. -- Configure bugmail: http://bugzilla.novell.com/userprefs.cgi?tab=email ------- You are receiving this mail because: ------- You are on the CC list for the bug.
http://bugzilla.novell.com/show_bug.cgi?id=554563 http://bugzilla.novell.com/show_bug.cgi?id=554563#c8 --- Comment #8 from Marco Poletti <poletti.marco@gmail.com> 2009-12-01 19:54:19 CET --- (In reply to comment #7)
Rui: A feeling tells me that we cannot do much about it, but you might want to have a look at the acpidump, so that you are aware of yet another busted ACPI brightness implementation...
About the hack: You might want to find an X-related entry point calling this. Or depending on your desktop, possibly you can add this to the kpowersave/powerdevil/gnome-power-management startup script?
I use KDE4, so powerdevil. Where is the script/config file I need to modify?
I close this as a BIOS bug -> won't fix.
Ok, I understand.
If a BIOS upgrade fixes this, please let us and other know about it.
I don't even hope that. My PC has been out for over one year and no BIOS updates have been released. -- Configure bugmail: http://bugzilla.novell.com/userprefs.cgi?tab=email ------- You are receiving this mail because: ------- You are on the CC list for the bug.
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