back light conflict i915 vs dell-laptop
Patrick Schaaf has reported that the i915 driver is setting his backlight very dim when he starts GDM.
https://bugzilla.kernel.org/show_bug.cgi?id=23472
It should be the dell-laptop platform driver controlling his backlight.
Gnome tries to restore the backlight settings through the dell_laptop interface in sysfs but it fails. (Because the platform hardware refuses to set the settings to what it thinks they already are).
regards,
dan carpenter
Quoted 10 lines · Dan Carpenter
Patrick Schaaf has reported that the i915 driver is setting his backlight very dim when he starts GDM.
https://bugzilla.kernel.org/show_bug.cgi?id=23472
It should be the dell-laptop platform driver controlling his backlight.
Gnome tries to restore the backlight settings through the
dell_laptopinterface in sysfs but it fails. (Because the platform hardware refuses to set the settings to what it thinks they already are).
I think I run into the same problem, xset dpms force standby is enough to trigger it, after that the backlight will never come up again. I need to suspend to ram to be able to see my screen again. The screen is on, just the backlight is off. Not dimmed to low level: completely off.
Ironically xset dpms force off will come up right... but all screen powermanagement will start with standby, so I'm stuck for the last few weeks in presentation mode to be able to work on 37-rc1... It was fine in .36 and it broke in 37-rc1.
I reported it to [email protected] on 8 Nov but got no reply.
If you need me to test something let me know. It's super annoying when I unplug the laptop and it exits presentation mode...
CONFIG_DRM_I915=yCONFIG_DRM_I915_KMS=y
Thanks,
Andrea
Quoted 10 lines · Dan Carpenter
Patrick Schaaf has reported that the i915 driver is setting his backlight very dim when he starts GDM.
https://bugzilla.kernel.org/show_bug.cgi?id=23472
It should be the dell-laptop platform driver controlling his backlight.
Gnome tries to restore the backlight settings through the
dell_laptopinterface in sysfs but it fails. (Because the platform hardware refuses to set the settings to what it thinks they already are).
As far as my instrumentation showed, gnome did try no such thing - there were no setting calls through the backlight interface when I switch between the GDM screen and text console.
I have now run with drm.debug=0x07 and noticed get/set backlight PWM messages from intel_panel_get/set_backlight which became lower and lower in value for each successive switching between GDM login screen and text console, until reaching a low point and overflowing to 255255.
I append the extract of these kernel messages, as well as putting them in the bugzilla entry linked above.
Hope this helps clarify the problems I'm seeing.
best regards
Patrick
Nov 28 18:43:17 lat1 kernel: [ 61.454973] [drm:intel_panel_get_backlight], get backlight PWM = 127500 Nov 28 18:43:17 lat1 kernel: [ 61.672115] [drm:intel_panel_set_backlight], set backlight PWM = 127500 Nov 28 18:43:25 lat1 kernel: [ 69.659366] [drm:intel_panel_get_backlight], get backlight PWM = 63627 Nov 28 18:43:25 lat1 kernel: [ 69.876223] [drm:intel_panel_set_backlight], set backlight PWM = 63627 Nov 28 18:45:02 lat1 kernel: [ 166.642624] [drm:intel_panel_get_backlight], get backlight PWM = 126735 Nov 28 18:45:02 lat1 kernel: [ 166.861225] [drm:intel_panel_set_backlight], set backlight PWM = 126735 Nov 28 18:45:06 lat1 kernel: [ 169.869343] [drm:intel_panel_get_backlight], get backlight PWM = 63246 Nov 28 18:45:06 lat1 kernel: [ 170.086225] [drm:intel_panel_set_backlight], set backlight PWM = 63246 Nov 28 18:50:24 lat1 kernel: [ 488.561922] [drm:intel_panel_get_backlight], get backlight PWM = 31563 Nov 28 18:50:24 lat1 kernel: [ 488.780228] [drm:intel_panel_set_backlight], set backlight PWM = 31563 Nov 28 18:50:29 lat1 kernel: [ 492.905273] [drm:intel_panel_get_backlight], get backlight PWM = 15776 Nov 28 18:50:29 lat1 kernel: [ 493.122220] [drm:intel_panel_set_backlight], set backlight PWM = 15776 Nov 28 18:50:45 lat1 kernel: [ 509.449869] [drm:intel_panel_get_backlight], get backlight PWM = 7888 Nov 28 18:50:45 lat1 kernel: [ 509.667228] [drm:intel_panel_set_backlight], set backlight PWM = 7888 Nov 28 18:50:48 lat1 kernel: [ 512.061427] [drm:intel_panel_get_backlight], get backlight PWM = 3944 Nov 28 18:50:48 lat1 kernel: [ 512.278220] [drm:intel_panel_set_backlight], set backlight PWM = 3944 Nov 28 18:50:54 lat1 kernel: [ 518.938610] [drm:intel_panel_get_backlight], get backlight PWM = 1972 Nov 28 18:50:55 lat1 kernel: [ 519.156232] [drm:intel_panel_set_backlight], set backlight PWM = 1972 Nov 28 18:50:58 lat1 kernel: [ 522.665295] [drm:intel_panel_get_backlight], get backlight PWM = 986 Nov 28 18:50:58 lat1 kernel: [ 522.883222] [drm:intel_panel_set_backlight], set backlight PWM = 986 Nov 28 18:51:04 lat1 kernel: [ 528.338612] [drm:intel_panel_get_backlight], get backlight PWM = 493 Nov 28 18:51:04 lat1 kernel: [ 528.557235] [drm:intel_panel_set_backlight], set backlight PWM = 493 Nov 28 18:51:07 lat1 kernel: [ 531.697225] [drm:intel_panel_get_backlight], get backlight PWM = 246 Nov 28 18:51:07 lat1 kernel: [ 531.915244] [drm:intel_panel_set_backlight], set backlight PWM = 246 Nov 28 18:51:20 lat1 kernel: [ 544.747370] [drm:intel_panel_get_backlight], get backlight PWM = 123 Nov 28 18:51:20 lat1 kernel: [ 544.965241] [drm:intel_panel_set_backlight], set backlight PWM = 123 Nov 28 18:51:24 lat1 kernel: [ 548.220386] [drm:intel_panel_get_backlight], get backlight PWM = 61 Nov 28 18:51:24 lat1 kernel: [ 548.437215] [drm:intel_panel_set_backlight], set backlight PWM = 61 Nov 28 18:51:31 lat1 kernel: [ 555.916888] [drm:intel_panel_get_backlight], get backlight PWM = 30 Nov 28 18:51:32 lat1 kernel: [ 556.134239] [drm:intel_panel_set_backlight], set backlight PWM = 30 Nov 28 18:51:35 lat1 kernel: [ 559.138346] [drm:intel_panel_get_backlight], get backlight PWM = 15 Nov 28 18:51:35 lat1 kernel: [ 559.355242] [drm:intel_panel_set_backlight], set backlight PWM = 15 Nov 28 18:51:40 lat1 kernel: [ 564.929606] [drm:intel_panel_get_backlight], get backlight PWM = 7 Nov 28 18:51:41 lat1 kernel: [ 565.148225] [drm:intel_panel_set_backlight], set backlight PWM = 7 Nov 28 18:51:45 lat1 kernel: [ 569.509391] [drm:intel_panel_get_backlight], get backlight PWM = 3 Nov 28 18:51:45 lat1 kernel: [ 569.726226] [drm:intel_panel_set_backlight], set backlight PWM = 3 Nov 28 18:51:52 lat1 kernel: [ 576.103569] [drm:intel_panel_get_backlight], get backlight PWM = 1 Nov 28 18:51:52 lat1 kernel: [ 576.322226] [drm:intel_panel_set_backlight], set backlight PWM = 1 Nov 28 18:51:56 lat1 kernel: [ 579.760386] [drm:intel_panel_get_backlight], get backlight PWM = 0 Nov 28 18:51:56 lat1 kernel: [ 579.977224] [drm:intel_panel_set_backlight], set backlight PWM = 255255 Nov 28 18:52:12 lat1 kernel: [ 596.022674] [drm:intel_panel_get_backlight], get backlight PWM = 127500 Nov 28 18:52:12 lat1 kernel: [ 596.241232] [drm:intel_panel_set_backlight], set backlight PWM = 127500 Nov 28 18:52:15 lat1 kernel: [ 599.502386] [drm:intel_panel_get_backlight], get backlight PWM = 63627 Nov 28 18:52:15 lat1 kernel: [ 599.719217] [drm:intel_panel_set_backlight], set backlight PWM = 63627
Quoted 10 lines · Dan Carpenter
Patrick Schaaf has reported that the i915 driver is setting his backlight very dim when he starts GDM.
https://bugzilla.kernel.org/show_bug.cgi?id=23472
It should be the dell-laptop platform driver controlling his backlight.
Gnome tries to restore the backlight settings through the
dell_laptopinterface in sysfs but it fails. (Because the platform hardware refuses to set the settings to what it thinks they already are).
As far as my instrumentation showed, gnome did try no such thing - there were no setting calls through the backlight interface when I switch between the GDM screen and text console.
I have now run with drm.debug=0x07 and noticed get/set backlight PWM messages from intel_panel_get/set_backlight which became lower and lower in value for each successive switching between GDM login screen and text console, until reaching a low point and overflowing to 255255.
I append the extract of these kernel messages, as well as putting them in the bugzilla entry linked above.
Hope this helps clarify the problems I'm seeing.
best regards
Patrick
Nov 28 18:43:17 lat1 kernel: [ 61.454973] [drm:intel_panel_get_backlight], get backlight PWM = 127500 Nov 28 18:43:17 lat1 kernel: [ 61.672115] [drm:intel_panel_set_backlight], set backlight PWM = 127500 Nov 28 18:43:25 lat1 kernel: [ 69.659366] [drm:intel_panel_get_backlight], get backlight PWM = 63627 Nov 28 18:43:25 lat1 kernel: [ 69.876223] [drm:intel_panel_set_backlight], set backlight PWM = 63627 Nov 28 18:45:02 lat1 kernel: [ 166.642624] [drm:intel_panel_get_backlight], get backlight PWM = 126735 Nov 28 18:45:02 lat1 kernel: [ 166.861225] [drm:intel_panel_set_backlight], set backlight PWM = 126735 Nov 28 18:45:06 lat1 kernel: [ 169.869343] [drm:intel_panel_get_backlight], get backlight PWM = 63246 Nov 28 18:45:06 lat1 kernel: [ 170.086225] [drm:intel_panel_set_backlight], set backlight PWM = 63246 Nov 28 18:50:24 lat1 kernel: [ 488.561922] [drm:intel_panel_get_backlight], get backlight PWM = 31563 Nov 28 18:50:24 lat1 kernel: [ 488.780228] [drm:intel_panel_set_backlight], set backlight PWM = 31563 Nov 28 18:50:29 lat1 kernel: [ 492.905273] [drm:intel_panel_get_backlight], get backlight PWM = 15776 Nov 28 18:50:29 lat1 kernel: [ 493.122220] [drm:intel_panel_set_backlight], set backlight PWM = 15776 Nov 28 18:50:45 lat1 kernel: [ 509.449869] [drm:intel_panel_get_backlight], get backlight PWM = 7888 Nov 28 18:50:45 lat1 kernel: [ 509.667228] [drm:intel_panel_set_backlight], set backlight PWM = 7888 Nov 28 18:50:48 lat1 kernel: [ 512.061427] [drm:intel_panel_get_backlight], get backlight PWM = 3944 Nov 28 18:50:48 lat1 kernel: [ 512.278220] [drm:intel_panel_set_backlight], set backlight PWM = 3944 Nov 28 18:50:54 lat1 kernel: [ 518.938610] [drm:intel_panel_get_backlight], get backlight PWM = 1972 Nov 28 18:50:55 lat1 kernel: [ 519.156232] [drm:intel_panel_set_backlight], set backlight PWM = 1972 Nov 28 18:50:58 lat1 kernel: [ 522.665295] [drm:intel_panel_get_backlight], get backlight PWM = 986 Nov 28 18:50:58 lat1 kernel: [ 522.883222] [drm:intel_panel_set_backlight], set backlight PWM = 986 Nov 28 18:51:04 lat1 kernel: [ 528.338612] [drm:intel_panel_get_backlight], get backlight PWM = 493 Nov 28 18:51:04 lat1 kernel: [ 528.557235] [drm:intel_panel_set_backlight], set backlight PWM = 493 Nov 28 18:51:07 lat1 kernel: [ 531.697225] [drm:intel_panel_get_backlight], get backlight PWM = 246 Nov 28 18:51:07 lat1 kernel: [ 531.915244] [drm:intel_panel_set_backlight], set backlight PWM = 246 Nov 28 18:51:20 lat1 kernel: [ 544.747370] [drm:intel_panel_get_backlight], get backlight PWM = 123 Nov 28 18:51:20 lat1 kernel: [ 544.965241] [drm:intel_panel_set_backlight], set backlight PWM = 123 Nov 28 18:51:24 lat1 kernel: [ 548.220386] [drm:intel_panel_get_backlight], get backlight PWM = 61 Nov 28 18:51:24 lat1 kernel: [ 548.437215] [drm:intel_panel_set_backlight], set backlight PWM = 61 Nov 28 18:51:31 lat1 kernel: [ 555.916888] [drm:intel_panel_get_backlight], get backlight PWM = 30 Nov 28 18:51:32 lat1 kernel: [ 556.134239] [drm:intel_panel_set_backlight], set backlight PWM = 30 Nov 28 18:51:35 lat1 kernel: [ 559.138346] [drm:intel_panel_get_backlight], get backlight PWM = 15 Nov 28 18:51:35 lat1 kernel: [ 559.355242] [drm:intel_panel_set_backlight], set backlight PWM = 15 Nov 28 18:51:40 lat1 kernel: [ 564.929606] [drm:intel_panel_get_backlight], get backlight PWM = 7 Nov 28 18:51:41 lat1 kernel: [ 565.148225] [drm:intel_panel_set_backlight], set backlight PWM = 7 Nov 28 18:51:45 lat1 kernel: [ 569.509391] [drm:intel_panel_get_backlight], get backlight PWM = 3 Nov 28 18:51:45 lat1 kernel: [ 569.726226] [drm:intel_panel_set_backlight], set backlight PWM = 3 Nov 28 18:51:52 lat1 kernel: [ 576.103569] [drm:intel_panel_get_backlight], get backlight PWM = 1 Nov 28 18:51:52 lat1 kernel: [ 576.322226] [drm:intel_panel_set_backlight], set backlight PWM = 1 Nov 28 18:51:56 lat1 kernel: [ 579.760386] [drm:intel_panel_get_backlight], get backlight PWM = 0 Nov 28 18:51:56 lat1 kernel: [ 579.977224] [drm:intel_panel_set_backlight], set backlight PWM = 255255 Nov 28 18:52:12 lat1 kernel: [ 596.022674] [drm:intel_panel_get_backlight], get backlight PWM = 127500 Nov 28 18:52:12 lat1 kernel: [ 596.241232] [drm:intel_panel_set_backlight], set backlight PWM = 127500 Nov 28 18:52:15 lat1 kernel: [ 599.502386] [drm:intel_panel_get_backlight], get backlight PWM = 63627 Nov 28 18:52:15 lat1 kernel: [ 599.719217] [drm:intel_panel_set_backlight], set backlight PWM = 63627
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Quoted 4 lines · Patrick Schaaf
Quoted 3 lines · Dan Carpenter
Patrick Schaaf has reported that the i915 driver is setting his backlight very dim when he starts GDM.
Quoted 8 lines
Quoted 7 lines
https://bugzilla.kernel.org/show_bug.cgi?id=23472
It should be the dell-laptop platform driver controlling his backlight.
Gnome tries to restore the backlight settings through the
dell_laptopinterface in sysfs but it fails. (Because the platform hardware refuses to set the settings to what it thinks they already are).
Keith Packard wrote in another thread that there were some patches to address this in his git repo:
git://people.freedesktop.org/~keithp/linux-2.6 drm-intel-next
regards,
dan carpenter
The dell laptop backlight problems I reported previously, are fixed with Indan's patch found here:
https://bugzilla.kernel.org/show_bug.cgi?id=23472#c32
which disables the is_backlight_combination_mode() function by making it return 0 immediately.
I'm running 2.6.37 with that patch applied, and the laptop is symptom free now.
best regards
Patrick
Quoted 7 lines · Patrick Schaaf
The dell laptop backlight problems I reported previously, are fixed with Indan's patch found here:
https://bugzilla.kernel.org/show_bug.cgi?id=23472#c32
which disables the
is_backlight_combination_mode()function by making it return 0 immediately.
I'd be happier in this case to disable the combination mode rather than ignore a value being used by the hardware to determine the backlight level. -Chris
Signature · 1 line
Chris Wilson, Intel Open Source Technology Centre