Re: Sunsetting PowerDevil's XRandrBrightness
Martin Steigerwald - 26.05.20, 14:35:39 CEST: > Hi Kai. > > Kai Uwe Broulik - 20.05.20, 21:31:07 CEST: > > PowerDevil has two (three, if you count DDC) means of controlling > > screen brightness: > > > > * Writing to sysfs (/sys/class/backlight and /sys/class/leds) > > * Using XRandr output property > > > > XRandR is doing X calls and we have some lovely animated screen > > brightness change. However, the UPower "backend" in PowerDevil is > > quite a spaghetti class and having multiple ways to control LEDs > > doesn't help. > > Read your blog post and tried the command there: > > % QT_LOGGING_RULES='powerdevil=true' > /usr/lib/x86_64-linux-gnu/libexec/ org_kde_powerdevil > > gave no output whatsoever. > > However as I am using the "modesetting" driver I bet it won't use > XRandR. > > Also that is on Debian Sid where KDE Frameworks currently is still at > 5.62. Sandro works on 5.70 currently. ThinkPad T520 with Intel > Sandybridge graphics. Actually I already had 5.69 from Debian experimental. 5.70 now coming in to unstable, so I can test again once it is available. -- Martin
Re: Sunsetting PowerDevil's XRandrBrightness
Hi Kai. Kai Uwe Broulik - 20.05.20, 21:31:07 CEST: > PowerDevil has two (three, if you count DDC) means of controlling > screen brightness: > > * Writing to sysfs (/sys/class/backlight and /sys/class/leds) > * Using XRandr output property > > XRandR is doing X calls and we have some lovely animated screen > brightness change. However, the UPower "backend" in PowerDevil is > quite a spaghetti class and having multiple ways to control LEDs > doesn't help. Read your blog post and tried the command there: % QT_LOGGING_RULES='powerdevil=true' /usr/lib/x86_64-linux-gnu/libexec/ org_kde_powerdevil gave no output whatsoever. However as I am using the "modesetting" driver I bet it won't use XRandR. Also that is on Debian Sid where KDE Frameworks currently is still at 5.62. Sandro works on 5.70 currently. ThinkPad T520 with Intel Sandybridge graphics. Best, -- Martin
Re: Sunsetting PowerDevil's XRandrBrightness
On Kubuntu 20.04 with Plasma 5.18, I'm not use xrandr: powerdevil: Backend loaded, loading core powerdevil: Core loaded, initializing backend powerdevil: Xrandr not supported, trying ddc, helper powerdevil: [DDCutilBrightness] compiled without DDC/CI support powerdevil: Falling back to helper to get brightness It looks like it is using /sys/devices/pci:00/:00:02.0/drm/card0/card0-eDP-1/intel_backlight The device is a laptop with Optimus and using Intel HD 630 for the display. -- Oded
Re: Sunsetting PowerDevil's XRandrBrightness
> One thing which this will trip over is, if device supports both XRandr > and normal backlight control, then code will prefer to still use the > XRandr, so not sure if we can "trust" data. That's on purpose, since XRandR has the smooth brightness animation, I always prefer that one, if possible. :) > Can we figure out some stats from e.g. bug reports and logs we have > available? Not sure, maybe. or KUserFeedback :D
Re: Sunsetting PowerDevil's XRandrBrightness
Hi Kai, On Wed, May 20, 2020 at 09:31:07PM +0200, Kai Uwe Broulik wrote: > XRandR is doing X calls and we have some lovely animated screen brightness > change. However, the UPower "backend" in PowerDevil is quite a spaghetti > class and having multiple ways to control LEDs doesn't help. I have one patchset work in progress to make upowerbackend not backend anymore, I will post that up for review later this week I think. > Can we get rid of the XRandrBrightness class and just use sysfs in every > case? You know what I will say! :D But, yes +1000! > XRandR Brightness doesn't work on Wayland, obviously, and the Intel > driver which supported it is dead. Are there any other GPU drivers or models > that use XRandR over sysfs? AMD, nvidia? I vaguely recall something but I > don't know for sure. Can we figure out some stats from e.g. bug reports and logs we have available? One thing which this will trip over is, if device supports both XRandr and normal backlight control, then code will prefer to still use the XRandr, so not sure if we can "trust" data. You'd need something like this to short-circuit the XRandR backend and verify that it still works with sysfs interface. https://invent.kde.org/plasma/powerdevil/snippets/935 > (We're super early in the 5.20 cycle, so if we rip it out now, we still have > four months to ignore any requests to put it back in ;) I agree with this. -- Bhushan Shah http://blog.bshah.in IRC Nick : bshah on Freenode GPG key fingerprint : 0AAC 775B B643 7A8D 9AF7 A3AC FE07 8411 7FBC E11D signature.asc Description: PGP signature
Sunsetting PowerDevil's XRandrBrightness
Hi all, PowerDevil has two (three, if you count DDC) means of controlling screen brightness: * Writing to sysfs (/sys/class/backlight and /sys/class/leds) * Using XRandr output property XRandR is doing X calls and we have some lovely animated screen brightness change. However, the UPower "backend" in PowerDevil is quite a spaghetti class and having multiple ways to control LEDs doesn't help. Can we get rid of the XRandrBrightness class and just use sysfs in every case? XRandR Brightness doesn't work on Wayland, obviously, and the Intel driver which supported it is dead. Are there any other GPU drivers or models that use XRandR over sysfs? AMD, nvidia? I vaguely recall something but I don't know for sure. (We're super early in the 5.20 cycle, so if we rip it out now, we still have four months to ignore any requests to put it back in ;) Cheers Kai Uwe
