Ubuntu РFglrx: No matching Device section for instance… found. how to fix it


I have HD 4850 card, Ubuntu 12.10 and installed legacy drivers using makson96 ppa.
The issue is, that FGLRX can not detect my device and loads vesa bios. I had the same problem on ubuntu 11.10, 12.04 versions. I want to manually help fglrx find a matching device to load as it shoudld do.

It is interesting, why does fglrx search for a device in a PCI:0@1:0:1 Bus?
in xorg.cof different bus is indicated:

Section "Device"
    Identifier  "aticonfig-Device[0]-0"
    Driver      "fglrx"
    BusID       "PCI:1:0:0"

display: :0.0  screen: 0
OpenGL vendor string: Advanced Micro Devices, Inc.
OpenGL renderer string: ATI Radeon HD 4800 Series         
OpenGL version string: 3.3.11653 Compatibility Profile Context

Here is a part of my xorg log:

[     3.846] (II) VESA: driver for VESA chipsets: vesa
[     3.846] (II) FBDEV: driver for framebuffer: fbdev
[     3.846] (++) using VT number 7

[     3.846] (WW) Falling back to old probe method for fglrx
[     3.883] (II) Loading PCS database from /etc/ati/amdpcsdb
[     3.883] (--) Assigning device section with no busID to primary device
[     3.883] (--) Chipset Supported AMD Graphics Processor (0x9442) found
[     3.884] (WW) fglrx: No matching Device section for instance (BusID PCI:0@1:0:1) found
[     3.884] (II) AMD Video driver is running on a device belonging to a group targeted for this release
[     3.884] (II) AMD Video driver is signed
[     3.884] (II) fglrx(0): pEnt->device->identifier=0xb7791d8f
[     3.884] (WW) Falling back to old probe method for vesa
[     3.884] (WW) Falling back to old probe method for fbdev

from lispci i foud out finally, that my video card is in 01:00.0 slot. logically, if fglrx searches for a vdeo card device in a wrong place, it will not find it.

01:00.0 VGA compatible controller: Advanced Micro Devices [AMD] nee ATI RV770 [Radeon HD 4850]

The log also says:

(WW) fglrx(0): board is an unknown third party board, chipset is supported
Thanks in advance.

Best Answer

I had the exact same card, 4850 and I found that fglrx even when configured properly takes up too much resources for the card. The best performance is shown when using the opensource driver. Do

sudo amdconfig --uninstall

and stick to the opensource driver is my suggestion as a user of that card for 3 years on Linux.