xf86-video-intel - enforce a given resolution on the DVI port?

Dag Bakke dag at bakke.com
Mon Feb 5 04:52:00 PST 2007

On 02/04/2007 09:40 PM, Keith Packard wrote:
> On Sun, 2007-02-04 at 13:46 +0100, Dag Bakke wrote:
>> Hi.
>> I have an Aopen minipc with an intel 915gm. It has a DVI port. Connected 
>> to that is my TV, with a DVI port and a 1366x768 LCD panel.
>> I cannot make the pc output 1366x768 on the DVI port, not even with the 
>> modesetting branch as of this morning. It firmly insists on 1024x768.
>> What causes this, and is there anything I can do to convince the 915gm 
>> chip that I really want it to produce 1366x768 on the DVI port no matter 
>> what the TV may have to say about its capabilities?
> By default, the driver picks a screen size from one of the monitors and
> sets all of the others as close as it can. So, the driver found a
> built-in LVDS through data in the BIOS (which you probably don't have)
> and set all of the outputs to that size (1024x768). The best thing to do
> at this point is disable the LVDS output, which will cause the server to
> skip that and use the DVI connector for the default size.
> With very new bits (which you appear to have), you can disable an output
> as follows:
> Section "Monitor"
> 	Identifier	"LCD"
> 	Option		"Ignore" "True"
> EndSection
> Section "Device"
> 	...
> 	Option		"monitor-LVDS" "LCD"
> EndSection

This worked. Sort of. I can get 1280x720. I guess the TV may be lying as 
well. The TV can do 1366x768 at 60Hz, no question about it. I have done it 
with ATI, and the documentation agrees.

> We have yet to discover a way to determine if an LVDS panel is
> connected, so we're continuing to guess based on the BIOS table data
> (which aopen doesn't bother to clear before selling hardware).

Hence my query for a way to instruct the gfx chip: "Yes, I sincerely 
want to blow up my monitor by feeding it invalid data. Fire!"
"Don't bother what you can detect or not. This the output port, this is 
the resolution, this is the refresh."
Which one could be led to believe the modesetting branch was all about.

I totally agree with the goal of being able to autodetect as much as 
possible and in the end elliminate the config file. But there will 
always be lazy/sloppy manufacturers, so being able to override stuff 
manually seems an inevitable requisite.

>> ./configure --prefix=/usr --disable-dri   causes the build to fail. If 
>> this is expected, perhaps the option should be removed?
> I don't think anyone has tested without DRI in a long time; please feel
> free to file a bug report so we won't forget to fix it at some point.


On 02/05/2007 12:18 PM, Barry Scott wrote:
 > FYI: All the 1366x768 displays that I have seen always report 1360x768
 > for computer use.
 > Barry

Mine appears to report 1280x720, Not sure I understand how to parse 
Xorg.0.log, but according to the manual, my TV can do

as well as all the regular ones. 1280x720 is not listed, by the way...

Dag B.

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