How to fix the physical size of a display in xrandr?

Question

In a nutshell, my problem is that my TV is overscanning and I have nothing like a "Screen Fit" option in the TV.

The TV is a Samsung model LN32R71B that I believe is providing a corrupted EDID file, as my /var/log/Xorg.0.log file contains an "Indeterminate output size" line related to this EDID file. Also, xrandr says that the output HDMI1 (this TV) has size 160mm x 90mm, but I think it should be 710mm x 400mm, because it is 32'' and 16:9 (see this Wikipedia entry). Moreover, the resolutions that xrandr shows for HDMI1 are completely different from the ones supported by the TV (as seen on its manual). I tried to manually use different officially supported resolutions without success, for instance, by doing:

cvt -v 1360 768 60.015
xrandr --newmode "1360x768_60.01"   84.75  1360 1432 1568 1776  768 771 781 798 -hsync +vsync
xrandr --addmode HDMI1 1360x768_60.01
xrandr --output HDMI1 --mode 1360x768_60.01

Also, I tried using gtf instead of cvt, but it did not work. More importantly, I tried to fix the physical size of HDMI1 by means of

xrandr --output HDMI1 --fbmm 710x400

, but it does not work, as executing xrandr keeps telling me that HDMI1 is still 160mm x 90mm. Can you help me?

P.S.: I am not completely sure that the EDID file is corrupt, because this TV works fine on a computer with Windows...

Edit 0:

My system is an Ubuntu 14.04 LTS 64-bit, and on the GPU info,

sudo lshw -C display

returns

  *-display               
       description: VGA compatible controller
       product: Broadwell-U Integrated Graphics
       vendor: Intel Corporation
       physical id: 2
       bus info: pci@0000:00:02.0
       version: 09
       width: 64 bits
       clock: 33MHz
       capabilities: msi pm vga_controller bus_master cap_list rom
       configuration: driver=i915 latency=0
       resources: irq:68 memory:c1000000-c1ffffff memory:d0000000-dfffffff ioport:5000(size=64)
  *-display
       description: Display controller
       product: Topaz XT [Radeon R7 M260]
       vendor: Advanced Micro Devices, Inc. [AMD/ATI]
       physical id: 0
       bus info: pci@0000:04:00.0
       version: 00
       width: 64 bits
       clock: 33MHz
       capabilities: pm pciexpress msi bus_master cap_list rom
       configuration: driver=fglrx_pci latency=0
       resources: irq:70 memory:b0000000-bfffffff memory:c0000000-c01fffff ioport:3000(size=256) memory:c2000000-c203ffff memory:c2040000-c205ffff

Answer 1

This probably won't help much but here's an xorg.conf fix for nVidia proprietary drivers. Not sure if this would be related to xrandr, & you don't mention what GPU your using to connect to the TV.

https://askubuntu.com/a/491498/486441

Just came across this one also Ubuntu 15.04 & ultrawide monitor. How to set max resolution? EDIT:Solved! using xrandr but had to create a xorg.conf

Answer 2

For the records, even though this might be semi-helpful: i had a similar problem and found here https://bbs.archlinux.org/viewtopic.php?id=171374 that this can be related to using an adapter. In my case i was using DP-to-HDMI adapter, and that was indeed responsible for wrong screen dimensions detected. I could solve it by not-using the adapter for that screen, but i guess not everyone has that option :/