Arch Linux

yourhereticself

Member

Registered: 2011-07-31

Posts: 3

[SOLVED] HDMI resolution and Radeon HD 4250

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)

yourhereticself

Member

Registered: 2011-07-31

Posts: 3

Re: [SOLVED] HDMI resolution and Radeon HD 4250

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.