Impossible to use 915GM/PM/GMS/910GML

[nimnull22]

Dear All.

00:02.0 VGA compatible controller: Intel Corporation Mobile 915GM/GMS/910GML Express Graphics Controller (rev 04)
00:02.1 Display controller: Intel Corporation Mobile 915GM/GMS/910GML Express Graphics Controller (rev 04)

This is my graphic controller.
I want to say, but unfortunately it is impossible to look on screen under ANY kernel higher then 2.6.30.
I have checked Fedora 12, 13, Rawhide - the same.
Disabling DRI2 in xorg.conf on rawhide make picture looks better, but far not what I have on 2.6.27. It feels like refresh rate is nor 60Hz. Picture is flickering. It start to hurt eyes after few hours.
It is really, really frustrating. I have checked kernels from other OS, 2.6.34-36 from OpenSuse 11.3 - the same. Some thing wrong with KMS or GEM, someone really screwed settings up, and left it. 2.6.27 shows picture much, much better, much smoother.
I will check updates, but not use. And more important that no one care.

[BugRocks1]

Notes I have about this kind of problem.
Video shimmering.


• Wrong phase/clock
• Sources:
∘ http://www.lagom.nl/lcd-test/
∘ http://www.techmind.org/lcd/
• Interference from electromagnetic source. i.e.: defective fluorescent lamps, radio emanations from cables.
• Solutions:
• Adjust the clock(a.k.a.: pixel clock, pclk, dot-clock, bandwidth) and the phase(a.k.a.: vertical refresh rate, refresh rate).
• Use shielded cabling.
• Use ferrite beads.
∘ http://en.wikipedia.org/wiki/Ferrite_bead
• Change the room illumination.

Besides that I was thinking that maybe it is a polarity problem so changing the vertical, horizontal or maybe both may cure that.

e.g.:
$ cvt 1600 1200 60
# 1600x1200 59.87 Hz (CVT 1.92M3) hsync: 74.54 kHz; pclk: 161.00 MHz
Modeline "1600x1200_60.00" 161.00 1600 1712 1880 2160 1200 1203 1207 1245 -hsync +vsync

Also using "skipddc" as a boot parameter may show some results.

---------- Post added at 05:52 PM CDT ---------- Previous post was at 05:37 PM CDT ----------

you can try also tweaking the vertical frequencies using cvt and xrandr.

But get the maximum vertical and horizontal frequencies for you equipment first.

Checking your pixel clock(pclk):
cat /var/log/Xorg.0.log | grep -i pixel

if you start X with verbose 6 it also shows the vertical and horizontal frequencies supported by the video card.

To see what your EDID says use:
su -
setenforce 0
monitor-edid
setenforce 1

e.g.:
# monitor-edid
Name: Acer X223W
EISA ID: ACR0009
Screen size: 47.3 cm x 29.6 cm (21.97 inches, aspect ratio 16/10 = 1.60)
Gamma: 2.2
Analog signal
Max video bandwidth: 170 MHz

HorizSync 30-83
VertRefresh 56-76

# Monitor preferred modeline (60.0 Hz vsync, 65.3 kHz hsync, ratio 16/10, 90 dpi)
ModeLine "1680x1050" 146.25 1680 1960 2136 2240 1050 1053 1059 1089 +hsync -vsync

---------- Post added at 05:54 PM CDT ---------- Previous post was at 05:52 PM CDT ----------

Note that the pixel clock(a.k.a. pclk, bandwidth) for the monitor and video card will be different, the card will be much higher then the monitor's.

---------- Post added at 07:31 PM CDT ---------- Previous post was at 05:54 PM CDT ----------

Ok, for the lazy in all of us here in two lines :)

su -
setenforce 0 && monitor-edid && setenforce 1 && sestatus

[nimnull22]

Thanks for replay and for help.

I probably have to say sorry, for confusing you a little bit.
I use laptop, LVSD1, 1024x768, only 60Hz
Rawhide kernel 2.6.34-11.fc14.i686.PAE

Output of xorg:

[ 27.039] (II) intel(0): EDID vendor "AUO", prod id 9297
[ 27.040] (II) intel(0): Printing DDC gathered Modelines:
[ 27.040] (II) intel(0): Modeline "1024x768"x0.0 65.00 1024 1048 1184 1344 768 771 777 806 -hsync -vsync (48.4 kHz)
...
[ 27.040] (II) intel(0): Printing probed modes for output LVDS1
[ 27.040] (II) intel(0): Modeline "1024x768"x60.0 65.00 1024 1048 1184 1344 768 771 777 806 -hsync -vsync (48.4 kHz)
[ 27.040] (II) intel(0): Modeline "800x600"x60.3 40.00 800 840 968 1056 600 601 605 628 +hsync +vsync (37.9 kHz)
[ 27.040] (II) intel(0): Modeline "800x600"x56.2 36.00 800 824 896 1024 600 601 603 625 +hsync +vsync (35.2 kHz)
[ 27.040] (II) intel(0): Modeline "640x480"x59.9 25.18 640 656 752 800 480 490 492 525 -hsync -vsync (31.5 kHz)
[ 27.040] (II) intel(0): Output LVDS1 connected

Output of the xrandr --verbose:
Screen 0: minimum 320 x 200, current 1024 x 768, maximum 4096 x 4096
LVDS1 connected 1024x768+0+0 (0x42) normal (normal left inverted right x axis y axis) 304mm x 228mm
Identifier: 0x41
Timestamp: 25694
Subpixel: horizontal rgb
Clones:
CRTC: 1
CRTCs: 1
Transform: 1.000000 0.000000 0.000000
0.000000 1.000000 0.000000
0.000000 0.000000 1.000000
filter:
EDID:
00ffffffffffff0006af512400000000
010f0103801e17780a87f594574f8c27
27505400000001010101010101010101
01010101010164190040410026301888
360030e4100000180000000f00000000
00000000000000000020000000fe0041
554f0a202020202020202020000000fe
004231353058473032205634200a0000
scaling mode: Full
supported: None Full Center Full aspect
1024x768 (0x42) 65.0MHz -HSync -VSync *current +preferred
h: width 1024 start 1048 end 1184 total 1344 skew 0 clock 48.4KHz
v: height 768 start 771 end 777 total 806 clock 60.0Hz
800x600 (0x43) 40.0MHz +HSync +VSync
h: width 800 start 840 end 968 total 1056 skew 0 clock 37.9KHz
v: height 600 start 601 end 605 total 628 clock 60.3Hz
800x600 (0x44) 36.0MHz +HSync +VSync
h: width 800 start 824 end 896 total 1024 skew 0 clock 35.2KHz
v: height 600 start 601 end 603 total 625 clock 56.2Hz
640x480 (0x45) 25.2MHz -HSync -VSync
h: width 640 start 656 end 752 total 800 skew 0 clock 31.5KHz
v: height 480 start 490 end 492 total 525 clock 59.9Hz

As you can see - everything looks very nice.
And what is really pity, on my OpenSuse 11.1 with kernel 2.6.27 i got the same "modeline", but LCD shows differently, much better. And eyes don't hurt after an hour.

But on kernels 32, 33, 34 - picture is rough, it is not smooth, something wrong with it. I do not know what, but eyes see it, I just see the difference, because it is on the same laptop, on different partitions.

Thanks.

---------- Post added at 08:59 PM CDT ---------- Previous post was at 08:32 PM CDT ----------

Ok, booted on OpenSuse 11.1. Here is output of her xrandr --verbose:

Screen 0: minimum 320 x 200, current 1024 x 768, maximum 2048 x 1200
LVDS connected 1024x768+0+0 (0x3c) normal (normal left inverted right x axis y axis) 304mm x 228mm
Identifier: 0x3b
Timestamp: 28701
Subpixel: horizontal rgb
Clones:
CRTC: 1
CRTCs: 1
EDID_DATA:
00ffffffffffff0006af512400000000
010f0103801e17780a87f594574f8c27
27505400000001010101010101010101
01010101010164190040410026301888
360030e4100000180000000f00000000
00000000000000000020000000fe0041
554f0a202020202020202020000000fe
004231353058473032205634200a0000
PANEL_FITTING: full
supported: center full_aspect full
BACKLIGHT_CONTROL: combination
supported: native legacy combination kernel
BACKLIGHT: 15625 (0x00003d09) range: (0,15625)
1024x768 (0x3c) 65.0MHz -HSync -VSync *current +preferred
h: width 1024 start 1048 end 1184 total 1344 skew 0 clock 48.4KHz
v: height 768 start 771 end 777 total 806 clock 60.0Hz
800x600 (0x3d) 40.0MHz +HSync +VSync
h: width 800 start 840 end 968 total 1056 skew 0 clock 37.9KHz
v: height 600 start 601 end 605 total 628 clock 60.3Hz
640x480 (0x3e) 25.2MHz -HSync -VSync
h: width 640 start 656 end 752 total 800 skew 0 clock 31.5KHz
v: height 480 start 490 end 492 total 525 clock 59.9Hz

The only difference I can see it is:
Screen 0: minimum 320 x 200, current 1024 x 768, maximum 4096 x 4096
LVDS1 connected 1024x768+0+0 (0x42) normal (normal left inverted right x axis y axis) 304mm x 228mm

Screen 0: minimum 320 x 200, current 1024 x 768, maximum 2048 x 1200
LVDS connected 1024x768+0+0 (0x3c) normal (normal left inverted right x axis y axis) 304mm x 228mm

[BugRocks1]

According to this post he solved his problem messing with the refresh rate(vertical frequency)
http://ubuntuforums.org/showpost.php?p=9245460&postcount=7

You can do the same using cvt and xrandr.

---------- Post added at 02:16 AM CDT ---------- Previous post was at 02:13 AM CDT ----------

http://www.techmind.org/lcd/phasexplan.html

Does your monitor have any phase/clock controls? I didn't read the manual and you have the physical thing in front of you so there could be some controls on the sides maybe.

[nimnull22]

Thanks for help.
But I use laptop, my LCD on laptop, I can't change refresh rate to whatever I want. I have only this:
[ 27.040] (II) intel(0): Printing probed modes for output LVDS1
[ 27.040] (II) intel(0): Modeline "1024x768"x60.0 65.00 1024 1048 1184 1344 768 771 777 806 -hsync -vsync (48.4 kHz)
[ 27.040] (II) intel(0): Modeline "800x600"x60.3 40.00 800 840 968 1056 600 601 605 628 +hsync +vsync (37.9 kHz)
[ 27.040] (II) intel(0): Modeline "800x600"x56.2 36.00 800 824 896 1024 600 601 603 625 +hsync +vsync (35.2 kHz)
[ 27.040] (II) intel(0): Modeline "640x480"x59.9 25.18 640 656 752 800 480 490 492 525 -hsync -vsync (31.5 kHz)

---------- Post added at 01:53 PM CDT ---------- Previous post was at 12:00 PM CDT ----------

My previous post was not true.
I can change vertical frequency. There is GTF and CVT, they give me different values and non of them similar to
27.040] (II) intel(0): Printing probed modes for output LVDS1
[ 27.040] (II) intel(0): Modeline "1024x768"x60.0 65.00 1024 1048 1184 1344 768 771 777 806 -hsync -vsync (48.4 kHz)

I have no idea how Xorg managed to get it.

And another question, my video card can provide 1024x768 on 60Hz, but I can give it 60,1 - 60,5. How can I find out what the limit ? 65Hz, or 61Hz.

[BugRocks1]

Using "monitor-edid" see the explanation from before. X get the vertical and horizontal frequencies by receiving the EDID and apparently in linux it receives that data from the video card that receives the data from the monitor

CVT doesn't use the edid so you have to verify the frequencies as to not go above the vertical and horizontal it could be bad in some cases if you do, and by bad I mean it could damage your monitor. For what can happen read this:
http://en.tldp.org/HOWTO/XFree86-Video-Timings-HOWTO/overd.html

The frequencies you are using and you know they work are in the range of 48.4-31.5 vertical sync so you can use those

e.g.:
cvt 1024 768 48.4

The cvt syntax is easy "cvt [horizontal] [vertical] [vertical refresh rate]"

---------- Post added at 02:14 PM CDT ---------- Previous post was at 02:07 PM CDT ----------

If you want to undestand what is going on with that you can read this:

http://en.tldp.org/HOWTO/XFree86-Video-Timings-HOWTO/
http://www.arachnoid.com/modelines/
http://wiki.mandriva.com/en/Tools/monitor-edid

Online modeline generator with advanced controls(see the bottom).
http://xtiming.sourceforge.net/cgi-bin/xtiming.pl

---------- Post added at 02:16 PM CDT ---------- Previous post was at 02:14 PM CDT ----------

I have one question.

Does changing the resolution to another one shows the shimmering?

If it doesn't get the frequency it is using and put that on your new modeline.

---------- Post added at 02:22 PM CDT ---------- Previous post was at 02:16 PM CDT ----------

Humor note:

You are about to become proficient in the use of xrandr.

[fibster]

have you tried at boot up, xdriver=free

[nimnull22]

# monitor-edid
mmap /dev/mem: Permission denied
EISA ID: AUO2451
EDID version: 1.3
EDID extension blocks: 0
Screen size: 30.4 cm x 22.8 cm (14.96 inches, aspect ratio 4/3 = 1.33)
Gamma: 2.2
Digital signal

# Monitor preferred modeline (60.0 Hz vsync, 48.4 kHz hsync, ratio 4/3, 85 dpi)
ModeLine "1024x768" 65 1024 1048 1184 1344 768 771 777 806 -hsync -vsync

Whatever I do with it picture is bad, hurts eyes, even if it is not flickering.
I do not know what to do, I just can't see it more then an hour.
New kernel+xorg server is just piece of ****.
When I boot on 2.6.27 it is like a present.
F*** it up. I will update rawhide of course, but no more. Will see, may be someday something changes "by it self". But looks like GEM+KMS+1.8.0 server is not for i915GM.
Hope everyone else happy with their screen picture quality.
Fortunately, I have 2.6.27 to compare with and I felt the difference.

Thanks for help.

[kyryder]

I suspect you may have a hardware issue. I have 2 multi boot laptops with I915GM cards with updated F12,F13 and F14 kojihide. I am experiencing no video issues.

Ky

[nimnull22]

I do not know what do you mean by hardware issue.
I have:
00:02.1 Display controller: Intel Corporation Mobile 915GM/GMS/910GML Express Graphics Controller (rev 04)
Subsystem: Lenovo Device 2062

And I had NO problems at all with picture on Mandriva, OpenSusu, Ubuntu, with kernels up to 2.6.27.

But I have problem to see picture with kernel 2.6.32,33,34, I checked allready OpenSuse 11.3, Fedoras - 12,13,14.
I even put 2.6.34-36 from suse 11.3 kernel to my current suse 11.1 and got the same awful screen output.

So may be it is crappy hardware, who knows.

[BugRocks1]

Here are some more sugestions:

- In /boot/grub/grub.conf edit the lines:

timeout=0 to
timeout=10

and

hiddenmenu
to
#hiddenmenu

That will give you a menu at start up where you can choose the kernel and also get into the grub command line pressing "c".

Doing that you can test without modfying anything permanently to test these boot parameters:

skipddc
nomodeset
i915.modeset=0

One at a time that means 3 reboots.

KMS or Kernel Modesetting in the last 5 years has been a source of pain that is why people keep telling other to use the nomodeset parameter everychance they got what they don't do is tell you to also report that to the guy's responsible for your drivers in this case you need to go to intel support and complain to them if nomodset or i915.modeset=0 works and solve your issues.

Also you can try changing the acceleration mode in /etc/X11/xorg.conf toggling between XAA and EXA.

Sources:
http://en.wikipedia.org/wiki/Mode-setting
http://kerneltrap.org/node/8242
http://fedoraproject.org/wiki/Xorg/Debugging

Information Resources:
∘ http://en.wikipedia.org/wiki/Display_Data_Channel
∘ http://en.wikipedia.org/wiki/Extended_display_identification_data
∘ http://www.x.org/releases/X11R7.5/doc/man/man1/
∘ https://fedorahosted.org/hwdata/
∘ http://fedoraproject.org/wiki/Xorg/3rdPartyVideoDrivers
∘ http://en.tldp.org/HOWTO/XFree86-Video-Timings-HOWTO/
∘ http://wiki.mandriva.com/en/Tools/monitor-edid
∘ http://www.lagom.nl/lcd-test/
∘ http://www.techmind.org/lcd/
∘ http://en.wikipedia.org/wiki/Liquid_crystal_display
∘ http://www.arachnoid.com/modelines/
∘ http://xtiming.sourceforge.net/cgi-bin/xtiming.pl
∘ http://www.redhat.com/docs/manuals/linux/RHL-9-Manual/install-guide/ch-bootopts.html
∘ http://en.wikipedia.org/wiki/Mode-setting
∘ http://kerneltrap.org/node/8242
∘ http://en.wikipedia.org/wiki/EXA (X acceleration mode new EXA to be deprecated)
∘ http://en.wikipedia.org/wiki/XFree86_Acceleration_Architecture (X acceleration mode old XAA)
∘ http://cgit.freedesktop.org/xorg/xserver/tree/hw/xfree86/xaa/XAA.HOWTO
∘ http://xorg.freedesktop.org/wiki/ExaStatus
∘ http://en.wikipedia.org/wiki/VDPAU
∘ http://en.wikipedia.org/wiki/X_video_extension
∘ http://fedoraproject.org/wiki/Xorg/Debugging

---------- Post added at 08:47 PM CDT ---------- Previous post was at 08:40 PM CDT ----------

To have the old X working as it was a long time ago one only needs to add nomodeset and XAA and maybe skipddc :)