xorg driver doesn't use my radeon videocard 14.04

Question

I have a Dell Inspiron 5521 laptop with a Radeon HD 8730M videocard, running Ubuntu 14.04

However, when I use the X.Org X server open source drivers from xserver-xorg-video-ati, the computer uses Intel Ivybridge Mobile for graphics.

glxinfo has the line: OpenGL renderer string: Mesa DRI Intel(R) Ivybridge Mobile x86/MMX/SSE2.

lspci | grep -i radeon gives the following result:

01:00.0 VGA compatible controller: Advanced Micro Devices, Inc. [AMD/ATI] Mars [Radeon HD 8730M] (rev ff)

When I use the fglrx proprietary drivers, the radeon card is used, but many other problems arise.

EDIT:

In /var/log/kern.log are the following lines. The first three lines are shown on the screen when starting the computer.

Nov 10 18:41:05 Computosaur kernel: [    6.679366] [drm:radeon_uvd_send_upll_ctlreq] *ERROR* Timeout setting UVD clocks!
Nov 10 18:41:05 Computosaur kernel: [    6.679397] [drm:uvd_v1_0_ib_test] *ERROR* radeon: failed to raise UVD clocks (-110).
Nov 10 18:41:05 Computosaur kernel: [    6.679425] [drm:radeon_ib_ring_tests] *ERROR* radeon: failed testing IB on ring 5 (-110).
Nov 10 18:41:05 Computosaur kernel: [    6.679778] [drm] Radeon Display Connectors
Nov 10 18:41:05 Computosaur kernel: [    6.685426] [drm] Internal thermal controller without fan control
Nov 10 18:41:05 Computosaur kernel: [    6.685495] [drm] probing gen 2 caps for device 8086:151 = 261ac82/6
Nov 10 18:41:06 Computosaur kernel: [    7.833374] [drm] radeon: dpm initialized
Nov 10 18:41:06 Computosaur kernel: [    7.833454] radeon 0000:01:00.0: No connectors reported connected with modes
Nov 10 18:41:06 Computosaur kernel: [    7.833456] [drm] Cannot find any crtc or sizes - going 1024x768
Nov 10 18:41:06 Computosaur kernel: [    7.834861] [drm] fb mappable at 0xA1480000
Nov 10 18:41:06 Computosaur kernel: [    7.834863] [drm] vram apper at 0xA0000000
Nov 10 18:41:06 Computosaur kernel: [    7.834863] [drm] size 3145728
Nov 10 18:41:06 Computosaur kernel: [    7.834864] [drm] fb depth is 24
Nov 10 18:41:06 Computosaur kernel: [    7.834865] [drm]    pitch is 4096
Nov 10 18:41:06 Computosaur kernel: [    7.834944] radeon 0000:01:00.0: fb1: radeondrmfb frame buffer device
Nov 10 18:41:06 Computosaur kernel: [    7.834957] [drm] Initialized radeon 2.36.0 20080528 for 0000:01:00.0 on minor 1

Answer 1

To actually use hybrid graphics, you have to use the fglrx driver.

There are many other things fglrx can do which xserver-xorg-video-ati can't. An example is frequency change of an AMD APU with an integrated Radeon chip, like the AMD A8 series.

What you could try is to install the latest fglrx build from AMD's website. However, you can't be sure whether this build will actually work (and not crash your OS). So you might first want to install it in a Live System with a persistency. Best use UNetBootin for this.

If this latest build doesn't fix it for you, you have to decide between using the Radeon card and suffer from the other problems you mentioned, or only use the embedded Intel Ivybridge chip, but without the other problems.