During installation IBM P50 on Matrox G400 not detected correctly.

[Michal Suchanek]

The monitor works fine with the HorizSync and VertRefresh lines created by
install scripts commented out.
I think the refresh rates should be specified in xorg.conf only when the monitor
cannot be detected by X automatically.

[Michal Suchanek (hramrach)]

Created an attachment (id=3036)
xorg.conf

[Michal Suchanek (hramrach)]

Created an attachment (id=3037)
xorl.log

[Michal Suchanek (hramrach)]

Created an attachment (id=3038)
xresprobe.log

[Michal Suchanek (hramrach)]

Created an attachment (id=3039)
ddcprobe.log

[Henrik Nilsen Omma (henrik)]

Hello,

Have you had a chance to test your hardware with dapper (a live CD perhaps)? If so are you still seeing this problem? Thanks.

- Henrik

[Fabio Massimo Di Nitto (fabbione)]

you tell me a solution without explaining me the problem. Does X work with the HorizSync and VertREfresh generated lines or not?

Fabio

[Michal Suchanek (hramrach)]

You see, the monitor is capable of 85Hz but the VertRefresh in xorg.conf (which was generated by the installer and wich I commented out) would limit it to 72Hz.
I will try if I can reproduce it with Dapper.

Thanks
Michal

[Fabio Massimo Di Nitto (fabbione)]

The problem is that your monitor does not return (in DDC) any freq range as you can see from xresprobe.log and VertRefresh is set to a failsafe default that still allows the frequency detected.

Not writing the combo of Vert/Horiz will break many other cards/monitor combinations.

At this point i am not even sure i can cosinder this bug but an enanchment request since the monitor does work at 72Hz.

Fabio

[Michal Suchanek (hramrach)]

No, both the X server and ddcprobe can correctly read the 1024x768@85 timing form the monitor. Maybe xresprobe is just broken.
In xorg.log there is something about no ddc signal but a bit later the modes are reported correctly. Perhaps it is one of the many quirks of the mga driver. Or it is the other output that is not connected on the card.

Michal

[Michal Suchanek (hramrach)]

With Dapper Flight 6 the VertRefresh option produced by the installer limits the monitor even more to only 60Hz.

I won't call a CRT at this frequecy 'working'.

Michal

[Fabio Massimo Di Nitto (fabbione)]

the 1024x768@85 comes from VESA timing, not ddc info.

I will try not to write the info for the mga and see how it will explode.

Fabio

[Fabio Massimo Di Nitto (fabbione)]

Beta will not write Horiz/Vert with these conditions:

  * On fresh installs, if the display is not a lcd/lvds, there are not know
    syncs frequencies for the monitor and the card is mga, do NOT write
    SYNC_RANGES. It appears that mga can cope just fine parting vesa info too.
    (Closes Ubuntu: #19098)

the package is already uploaded and propagate the archive soon.

Fabio