[SOLVED] HDMI resolution and Radeon HD 4250

Question

Hello,
I am a noob to Arch. Iam sorry in advance for my ignorance. I have searched for a week on the wiki and forums and then gone back and re-read everything I have found. The answer is still eluding me. I am trying to connect my laptop to my tv through hdmi. I figured out the sound on my own, that was easy. I can't however get the native resolution for the tv. I have used xrandr and cvt as in the wiki. I have messed with a xorg.conf yet because it seems a bit confusing, but again, I'm a noob. Coming from ubuntu and that unity thing that just, well, anyway.
basically this is what i have done:
cvt 1366 768
xrandr --newmode "1368x768_60.00"   85.25  1368 1440 1576 1784  768 771 781 798 -hsync +vsync
xrandr --addmode HDMI-0 1366x768
xrandr --output HDMI-0 --mode 1366x768
and I get format not supported on my tv screen and yet that is the native resolution on the tv.
This is what I get with xrandr now:
[george@archbook ~]$ xrandr
Screen 0: minimum 320 x 200, current 2646 x 768, maximum 8192 x 8192
VGA-0 disconnected (normal left inverted right x axis y axis)
LVDS connected 1366x768+0+0 (normal left inverted right x axis y axis) 344mm x 194mm
1366x768 60.0*+
1280x720 59.9
1152x768 59.8
1024x768 59.9
800x600 59.9
848x480 59.7
720x480 59.7
640x480 59.4
HDMI-0 connected 1280x720+1366+0 (normal left inverted right x axis y axis) 16mm x 9mm
1280x720 60.0*+
720x480 59.9
1366x768 60.0
1368x768_60.00 (0x174) 85.2MHz
h: width 1368 start 1440 end 1576 total 1784 skew 0 clock 47.8KHz
v: height 768 start 771 end 781 total 798 clock 59.9Hz
I don't know what else to do. Is this a driver problem. Should I try the catalyst driver or is there a fix to this?
I'm sorry if there is already a thread for this. I've read through these forums and after a week I decided to finally post my question. If there is another thread please provide me with the link as I have missed it. If there is not, anyone have any ideas?
Last edited by yourhereticself (2011-08-01 01:35:32)

Answer 1

So I solved this myself last night, however, it seems I was so caught up in trying to get the native resolution of my tv detected I did not realize that my sound is still not fuctional (I had it working in gnome 3, but i decided to switch to kde and kmix recognizes that there is hdmi but includes no channels for control of the volmue). so any way...
i solution to getting 1366x768 resolution through hdmi is: apparently 1366x768 is not a recognized mode which is why cvt gives the modeline for 1368x768; however, I 1360x768 is recognized (which I think is a fair comprimize). It looks decent on my setup anyway. So for anyone who actually has their hdmi sound working here is the solution:
$ cvt 1360 768
# 1360x768 59.80 Hz (CVT) hsync: 47.72 kHz; pclk: 84.75 MHz
Modeline "1360x768_60.00" 84.75 1360 1432 1568 1776 768 771 781 798 -hsync +vsync
then take the modeline and create a new mode using xrandr as such:
$ xrandr --newmode "1360x768_60.00" 84.75 1360 1432 1568 1776 768 771 781 798 -hsync +vsync
then add the newcode to HDMI-0 as such making sure you replace "0" in HDMI-0 with the number of the HDMI port you are planning to use:
$xrandr --addmode HDMI-0 1360x768_60.00
then change your output to this resolution via:
xrandr --output HDMi-0 --mode 1360x768_60.00
If anyone knows who to get the proper channels in kmix to control hdmi sound please let me know. Otherwise I am going to switch vga and headphone out jack for now. Thanks.