Switchable graphics ATI Mobility Radeon HD 5xxx Series don't work in Ubuntu

In Ubuntu 12.04, the switchable graphics ATI Mobility Radeon HD 5xxx Series don't work. It was working previously with the catalyst driver from the ATI website in Ubuntu 11.10 or 11.04 (I don't remember).

With the free dirver, Intel and ATI cards are running together. We can't choose one of them nor power off the second one. Thus the battery of the laptop dies quickly.

Using jockey to install the "ATI/AMD proprietary FGLRX graphics driver", there isn't error during the installation process, but the 3D does not work after reboot:

$ fglrxinfo
X Error of failed request: BadRequest (invalid request code or no such operation)
  Major opcode of failed request: 154 (GLX)
  Minor opcode of failed request: 19 (X_GLXQueryServerString)
  Serial number of failed request: 12
  Current serial number in output stream: 12

$ fgl_glxgears
Using GLX_SGIX_pbuffer
X Error of failed request: BadRequest (invalid request code or no such operation)
  Major opcode of failed request: 154 (GLX)
  Minor opcode of failed request: 19 (X_GLXQueryServerString)
  Serial number of failed request: 12
  Current serial number in output stream: 12

If I choose "ATI/AMD proprietary FGLRX graphics driver (post-release updates)", the installation failes:

2012-04-26 17:26:57,579 WARNING: /sys/module/fglrx_updates/drivers does not exist, cannot rebind fglrx_updates driver
2012-04-26 17:27:20,726 DEBUG: fglrx.enabled(fglrx_updates): target_alt None current_alt /usr/lib/fglrx/ld.so.conf other target alt None other current alt /usr/lib/fglrx/alt_ld.so.conf
2012-04-26 17:27:20,727 DEBUG: fglrx_updates is not the alternative in use
2012-04-26 17:27:20,753 DEBUG: fglrx.enabled(fglrx_updates): target_alt None current_alt /usr/lib/fglrx/ld.so.conf other target alt None other current alt /usr/lib/fglrx/alt_ld.so.conf
2012-04-26 17:27:20,753 DEBUG: fglrx_updates is not the alternative in use

Finaly, the catalyst drivers from ATI website (12.4 and 12.6) break X11 after rebooting. We can still uninstall the driver with the tty.

It's a known issue, see http://ubuntuforums.org/showthread.php?t=1930450 and http://ubuntuforums.org/showthread.php?t=1966649

System informations:

$ lspci|grep VGA
00:02.0 VGA compatible controller: Intel Corporation Core Processor Integrated Graphics Controller (rev 02)
01:00.0 VGA compatible controller: Advanced Micro Devices [AMD] nee ATI Manhattan [Mobility Radeon HD 5400 Series]

$ sudo lshw -C display
  *-display
       description: VGA compatible controller
       product: Manhattan [Mobility Radeon HD 5400 Series]
       vendor: Hynix Semiconductor (Hyundai Electronics)
       physical id: 0
       bus info: pci@0000:01:00.0
       version: 00
       width: 64 bits
       clock: 33MHz
       capabilities: pm pciexpress msi vga_controller bus_master cap_list rom
       configuration: driver=radeon latency=0
       resources: irq:46 memory:a0000000-afffffff memory:c4400000-c441ffff ioport:4000(size=256) memory:c4440000-c445ffff
  *-display
       description: VGA compatible controller
       product: Core Processor Integrated Graphics Controller
       vendor: Intel Corporation
       physical id: 2
       bus info: pci@0000:00:02.0
       version: 02
       width: 64 bits
       clock: 33MHz
       capabilities: msi pm vga_controller bus_master cap_list rom
       configuration: driver=i915 latency=0
       resources: irq:43 memory:c0000000-c03fffff memory:b0000000-bfffffff ioport:5050(size=8)

$ lsb_release -a
No LSB modules are available.
Distributor ID: Ubuntu
Description: Ubuntu 12.04 LTS
Release: 12.04
Codename: precise

$ uname -a
Linux laptop 3.2.0-23-generic #36-Ubuntu SMP Tue Apr 10 20:39:51 UTC 2012 x86_64 x86_64 x86_64 GNU/Linux

$ xrandr
Screen 0: minimum 320 x 200, current 1600 x 900, maximum 8192 x 8192
LVDS1 connected 1600x900+0+0 (normal left inverted right x axis y axis) 382mm x 215mm
   1600x900 60.1*+
   1440x900 59.9
   1360x768 59.8 60.0
   1152x864 60.0
   1024x768 60.0
   800x600 60.3 56.2
   640x480 59.9
VGA1 disconnected (normal left inverted right x axis y axis)