[CentOS] Re: centos] Video driver for IBM Netvista w/Intel 845 chipset

[R P Herrold]

On Sun, 12 Mar 2006, Thomas E Dukes wrote:

> I am having problems with video in X.  I get an over 
> frequency issue using the stock CentOS 4.2 driver.  I have 
> searched IBM and Intel for the driver but no luck. 
> Occassionally I see something about need to load a kernel 
> module for agpgart.  How do I do this?  Anyone have a 
> similar setup or know where I can find the driver?

The issue is really the Intel onboard video hardware [which 
IBM Netvista have with the 845 chipset, and older HP units 
have at the 810 and 815 chipsets; newer Dell kit have 9xx 
series onboard video], which is at best moderately well 
supported

The bugs which Mike Harris upstream has had on Intel kit, and 
his discussions on the devel mailing lists, show much that 
Intel could do better.  ;)  It turns out the Intel video 
hardware bios cannot be persistently have mode settings 
reprogrammed - one has to do it on the fly at boot time before 
X starts running.

The doco on the xorg.conf file could be better, but one can 
plow through it and find some help with our friend Google.

I had to use a program called '915resolution' from 
http://www.geocities.com/stomljen/ to remap video bios in ram, 
to support my (Westinghouse) panel monitor at 1440 x 1050 
($420 on sale at Best Buy last week - highly recommended). 
These is a similar tool for the Intex 8xx onboard video 
hardware.

I added an item to the R/L 5 initscripts, to run this in 
/etc/rc.d/rc5.d/ as S89videotweak, [right before the xfs 
starts up]:

#!/bin/sh
#       set up the Intel 865 chip for our Westinghouse monitor
/etc/rc.d/915resolution 4d 1440 1050 16
/etc/rc.d/915resolution 41 1152 864  16
/etc/rc.d/915resolution 43 1280 960  16
#

and my /etc/X11/x.org looks like this in relevant part:

Section "Monitor"
         Identifier   "Monitor0"
         VendorName   "Monitor Vendor"
         ModelName    "LTV-19w3"
         DisplaySize  410        260
         HorizSync    30.0 - 82.0
         VertRefresh  56.0 - 76.0
         Option      "dpms"
# 1440x1050 @ 68.00 Hz (GTF) hsync: 74.26 kHz; pclk: 144.95  MHz
         Modeline "4d"  144.95  1440 1536 1696 1952  1050 1051 1054 1092 -HSync +Vsync
         Modeline "41"  99.64   1152 1224 1344 1536  864 865 868 901  -HSync +Vsync
         Modeline "43"  124.54  1280 1368 1504 1728  960 961 964 1001 -HSync +Vsync
EndSection

Section "Device"
         Identifier  "Videocard0"
         Driver      "i810"
         VendorName  "Videocard vendor"
         BoardName   "Intel 865"
EndSection

Section "Screen"
         Identifier "Screen0"
         Device     "Videocard0"
         Monitor    "Monitor0"
         DefaultDepth     16
         SubSection "Display"
                 Viewport   0 0
                 Depth     16
#               Modes    "1280x960" "1152x864" "1024x768" "800x600" "640x480"
#       the default modes are there implicitly - enumerate the  additional ones
#               Modes "5c" "50" "52"    (these are 32 bit colors)
#               Modes "4d" "41" "43"    (these are 16 bit colors)
                 Modes "4d"
#       we drop scan rate for this last to accomodate the monitor
# $ gtf 1440 1050 66
# 1440x1050 @ 66.00 Hz (GTF) hsync: 72.01 kHz; pclk: 139.40 MHz
#  Modeline "5c"  139.40  1440 1536 1688 1936  1050 1051 1054 1091  -HSync +Vsync
         EndSubSection
EndSection

==========================

Note that redefined mode 4d buried down in there in the 
'Screen section -- I had to dink with 'gtf' and updating the 
Intel chip on the fly with these parameters to get it working 
well; I avoid the redefined modes 41 and 43, as they don't get 
that last pixel from the display, but they seem to work.  the 
32 bit colordepth is beyind the capabilities of the monitor - 
but 16 bit is sufficicent for my needs.

-- Russ Herrold