Low res screen modes

Just wondering if recent changes would be the reason why the low res modes I defined used to work & no longer do, not showing up in the Screen configuration util. They were;

# 320 x 250 (70Hz)
startmode
mode_name:320 x 250 (70Hz)
 x_res:320
 y_res:250
 pixel_rate:12587
 h_timings:42,14,12,320,12,0
 v_timings:2,109,0,250,0,88
 sync_pol:2
endmode

# 320 x 480 (60Hz)
startmode
mode_name:320 x 480 (60Hz)
 x_res:320
 y_res:480
 pixel_rate:12587
 h_timings:42,14,12,320,12,0
 v_timings:2,32,0,480,0,11
 sync_pol:3
endmode

I originally defined them for some games (can’t remember which) but given that my interest wasn’t really the games it may not be that recent the modes stopped working.

What hardware are you running on?

Oops, chopped that bit off in an edit. I was originally going to add to the EDID thread but it had moved on.

It’s a Beagleboard -xM driving a Dell 1505FP, the latter as supplied by your good self.

A few months ago we did some investigation into how well the BeagleBoard coped with low resolution modes (linky). The manual for the TFP410 DVI framer chip says it supports down to 25MHz, but we were able to get stable pictures down to 15MHz, so that’s where we’ve set the limit. If you’re able to get down to 12.5MHz then you must be pretty lucky, both in BeagleBoard and monitor department.

I’m not really sure what the best solution is here. Drop the limit to 12.5? Test things again? (I do have a HDMI→VGA adapter now, although like Sprow’s one it’s passively powered and so probably isn’t the best way of testing things). Finally implement hardware scaling support? (Although it would actually need to be software scaled for paletted modes on OMAP).

I guess I was lucky. I threw the monitor specs at MakeModes and it threw those configurations back. It worked. The last thing I would claim is that I knew what I was doing. :-)