HTPC linux hardware gotchas

[mirak63]

It should respect the modeline you specify. There's no code (in radeon at least) to not accept 24p modes. What happens when you try and specify one with xrandr?

xrandr --newmode <24p modeline>
xrandr --addmode <output> <24p mode name>
xrandr --output <output> --mode <24p mode name>

e.g. (change the output and mode bits to your setup),
xrandr --newmode "1920x1080_24.00" 63.00 1920 1976 2160 2400 1080 1083 1088 1098 -hsync +vsync
xrandr --addmode DVI-0 "1920x1080_24.00"
xrandr --output DVI-0 --mode "1920x1080_24.00"

I tried something else with proprietary drivers, I didn't came back to opensource drivers since they don't have vdpau.

$ gtf 1920 1080 50

  # 1920x1080 @ 50.00 Hz (GTF) hsync: 55.60 kHz; pclk: 141.45 MHz
  Modeline "1920x1080_50.00"  141.45  1920 2032 2232 2544  1080 1081 1084 1112  -HSync +Vsync

$ xrandr --newmode 1920x1080i50_5  141.45  1920 2032 2232 2544  1080 1081 1084 1112  -HSync +Vsync Interlace
$ xrandr --addmode default  1920x1080i50_5
$ xrandr --output default --mode 1920x1080i50_5

This should enable 1080i50, however the screen only goes to 1080p
This happens with the nvidia driver.

The problem is similar with custom modelines through xrandr and the radeon,radeonhd,nv drivers.

I didn't tried for proprietary driver in xorg.conf modelines, but for opensources drivers it doesn't work in xorg.conf

$ gtf 1920 1080 24
 # 1920x1080 @ 24.00 Hz (GTF) hsync: 26.28 kHz; pclk: 61.81 MHz
  Modeline "1920x1080_24.00"  61.81  1920 1944 2136 2352  1080 1081 1084 1095  -HSync +Vsync

$ xrandr --newmode 1920x1080p24 61.81  1920 1944 2136 2352  1080 1081 1084 1095  -HSync +Vsync 
$ xrandr --addmode default  1920x1080p24
$ xrandr --output default --mode 1920x1080p24

this one works with proprietary driver


edit:
I tried, and none of that works on the nv driver, even by adding modes to xorg.conf

$ xrandr --output default --mode 1920x1080p24

xrandr: Configure crtc 0 failed

[agd5f]

I can only help debug this on the open source radeon driver. I'm not familiar with the nv driver or nv hardware.