Bug 97839 - Eye strain possibly caussed by PWM configuration in xorg.
Summary: Eye strain possibly caussed by PWM configuration in xorg.
Status: NEEDINFO
Alias: None
Product: xorg
Classification: Unclassified
Component: Driver/intel (show other bugs)
Version: unspecified
Hardware: All Linux (All)
: medium major
Assignee: Chris Wilson
QA Contact: Intel GFX Bugs mailing list
URL:
Whiteboard:
Keywords:
Depends on:
Blocks:
 
Reported: 2016-09-17 04:01 UTC by ivan
Modified: 2016-09-22 04:12 UTC (History)
0 users

See Also:
i915 platform:
i915 features:


Attachments
Eye strain in linux. (999.94 KB, application/pdf)
2016-09-17 04:01 UTC, ivan
no flags Details
dmesg paste (33 bytes, text/plain)
2016-09-21 01:23 UTC, ivan
no flags Details
intel_reg dump paste (21.64 KB, text/plain)
2016-09-21 16:52 UTC, ivan
no flags Details
DMESG with module parameter (108.44 KB, text/plain)
2016-09-22 04:12 UTC, ivan
no flags Details

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Description ivan 2016-09-17 04:01:18 UTC
Created attachment 126586 [details]
Eye strain in linux.

Hi everyone, i come here to report a bug that is causing me a lot of problems.
Let start, i have 3 pcs, a hp netbook, a desktop pc and a asus laptop, always i tried to install some linux that i wanna use in that time, so now i'm using Windows 8.1 why?Always i come to windows sadly by the same reason:

EYE STRAIN.

While in Windows i can stay for 10 hours using the pc, watching videos, reading pdf, drawing,etc.In any linux distro i can't stay half hour and my eyes stars feel like drying, i really annoying effect, its unbearable for me and i think that in a long time could be dangerous, so i investigate about the theme.

The first that i found in internet was to use flu.x or redshift, sadly that doesn't work.
The second was the refresh rate, i think that could be but modifying with xrandr doesn't gave goos results.

The last info that i found was that the guilty in this case was the PWM,i suppose that is the problem i don't found more info.

https://en.wikipedia.org/wiki/LED-backlit_LCD

I found that linux use a really low pwm, so i tried to change it with the intel gpu tool, right i change i make the pen test and effectively the pwm solved, now the high brightness of the screen burn my eyes...

I tried the pen test in windows and i found that in the pwm is low in lower brightness but i not cause my eye strain, so i really don't now what i could do more. You now a lot more about this so i really thank your help.

I attached a pdf with the info about my screen, have a lot of stuff that i think that could be usefull.
Comment 1 Jani Nikula 2016-09-19 07:37:05 UTC
Which kernel version are you using?

Please attach /sys/kernel/debug/dri/0/i915_vbt. (Lacking that, /sys/kernel/debug/dri/0/i915_opregion.)

Please add drm.debug=14 module parameter, and attach dmesg from boot.

Please do a register dump using 'intel_reg dump' when you're experiencing the problem.

If you can figure out how, please do an MMIO dump of the graphics PCI bar on Windows. I think there are tools for this, but I'm no Windows user.
Comment 2 ivan 2016-09-20 03:14:16 UTC
I'm using 4.4 kernel, I don't found  the i915_vbt and i915_opregion, I used a live distro(Ubuntu), maybe I can't install to see if the files appear.
Can you explain me more about the register dump and the MMIO dump I don't understand how to use it.

There is the Intel_reg dump paste:
http://pastebin.ubuntu.com/23205444/

I will try to install again Linux for provide more info.
Comment 3 Jani Nikula 2016-09-20 08:05:33 UTC
(In reply to ivan from comment #2)
> I'm using 4.4 kernel, I don't found  the i915_vbt and i915_opregion, I used
> a live distro(Ubuntu), maybe I can't install to see if the files appear.

You'll need to have debugfs mounted and probably need root access for them.

> Can you explain me more about the register dump and the MMIO dump I don't
> understand how to use it.
> 
> There is the Intel_reg dump paste:
> http://pastebin.ubuntu.com/23205444/

Please *attach* the information.
Comment 4 ivan 2016-09-21 01:19:18 UTC
(In reply to Jani Nikula from comment #3)
> (In reply to ivan from comment #2)
> > I'm using 4.4 kernel, I don't found  the i915_vbt and i915_opregion, I used
> > a live distro(Ubuntu), maybe I can't install to see if the files appear.
> 
> You'll need to have debugfs mounted and probably need root access for them.
> 
> > Can you explain me more about the register dump and the MMIO dump I don't
> > understand how to use it.
> > 
> > There is the Intel_reg dump paste:
> > http://pastebin.ubuntu.com/23205444/
> 
> Please *attach* the information.

Like i see i have mounted the debugfs monted, i access with root and i still not found the i915_vbt and i915_opregion. I don't now if i'm making something wrong.
I found that debugfs is mounted on my distro when i installed.
Comment 5 ivan 2016-09-21 01:23:26 UTC
Created attachment 126684 [details]
dmesg paste

the dmesg paste. When you say of attach the file is this, right?, I'm new on this of report bugs.
Comment 6 ivan 2016-09-21 16:52:23 UTC
Created attachment 126711 [details]
intel_reg dump paste

Intel reg paste.
Comment 7 ivan 2016-09-21 22:55:09 UTC
(In reply to Jani Nikula from comment #1)
> If you can figure out how, please do an MMIO dump of the graphics PCI bar on
> Windows. I think there are tools for this, but I'm no Windows user.

Wait, i'm using a laptop how i can do an MMIO dump of a pci bar if a laptop?
I'm really new on this, i found that exist a software in windows called windbg, its the only that i found searching about MMIO dump.
Comment 8 ivan 2016-09-22 04:12:06 UTC
Created attachment 126721 [details]
DMESG with module parameter

I can't use the dmesg command in the grub, but when i add the module parameter to the boot, the dmesg gave me different results.
I hope that will be usefull.


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