By installing the catalyst driver with the default xserver-xorg-driver-intel I have the problem mentioned on this bug. Instead using your patch will solve the problem concerning the fglrx but if the user would like to remove the proprietary driver and restore the previous one, he needs to remove also your patch otherwise he will get low graphics mode. I was not able to login till I restored the original xserver-xorg-driver-intel.

PS: the radeon package will come with xserver-xorg-video-ati

In addition I have a segmentation fault shutting down the machine if igpu is active. Please have a look below. In parallel I will update the bug http://ati.cchtml.com/show_bug.cgi?id=460 because I think it is more a fglrx problem

------------[ cut here ]------------
Jan  5 20:59:37 Houston kernel: [   20.902685] WARNING: at /build/buildd/linux-3.5.0/drivers/pci/msi.c:828 pci_enable_msi_block+0x2a4/0x2b0()
Jan  5 20:59:37 Houston kernel: [   20.902686] Hardware name: HP Pavilion dv6 Notebook PC
Jan  5 20:59:37 Houston kernel: [   20.902687] Modules linked in: fglrx(PO) amd_iommu_v2 parport_pc ppdev snd_hda_codec_hdmi rfcomm bnep snd_hda_codec_idt hp_wmi sparse_keymap binfmt_misc joydev coretemp kvm ghash_clmulni_intel aesni_intel cryptd aes_x86_64 lib80211_crypt_tkip snd_hda_intel snd_hda_codec snd_hwdep snd_pcm snd_seq_midi snd_rawmidi hid_generic wmi snd_seq_midi_event snd_seq snd_timer snd_seq_device uvcvideo videobuf2_core videodev videobuf2_vmalloc videobuf2_memops usbhid mac_hid snd hid microcode wl(PO) btusb hp_accel i915 bluetooth psmouse lis3lv02d input_polldev serio_raw drm_kms_helper lp lib80211 parport drm soundcore snd_page_alloc lpc_ich mei rts_pstor(C) i2c_algo_bit video r8169 [last unloaded: amd_iommu_v2]
Jan  5 20:59:37 Houston kernel: [   20.902726] Pid: 1253, comm: Xorg Tainted: P         C O 3.5.0-21-generic #32-Ubuntu
Jan  5 20:59:37 Houston kernel: [   20.902727] Call Trace:
Jan  5 20:59:37 Houston kernel: [   20.902732]  [<ffffffff81051c1f>] warn_slowpath_common+0x7f/0xc0
Jan  5 20:59:37 Houston kernel: [   20.902735]  [<ffffffff81051c7a>] warn_slowpath_null+0x1a/0x20
Jan  5 20:59:37 Houston kernel: [   20.902737]  [<ffffffff8136c5c4>] pci_enable_msi_block+0x2a4/0x2b0
Jan  5 20:59:37 Houston kernel: [   20.902769]  [<ffffffffa0bb3b63>] KCL_RequestMSI+0x13/0x20 [fglrx]
Jan  5 20:59:37 Houston kernel: [   20.902798]  [<ffffffffa0bd3c8f>] IRQMGR_initialize+0x24f/0x380 [fglrx]
Jan  5 20:59:37 Houston kernel: [   20.902827]  [<ffffffffa0bd39e7>] ? IRQMGR_alloc_context+0xb7/0x110 [fglrx]
Jan  5 20:59:37 Houston kernel: [   20.902856]  [<ffffffffa0bd2c2e>] ? irqmgr_wrap_initialize+0x1e/0xb0 [fglrx]
Jan  5 20:59:37 Houston kernel: [   20.902884]  [<ffffffffa0bd3885>] ? firegl_irqmgr_init+0x55/0x100 [fglrx]
Jan  5 20:59:37 Houston kernel: [   20.902914]  [<ffffffffa0be4486>] ? hal_init_gpu+0x1d6/0x4b0 [fglrx]
Jan  5 20:59:37 Houston kernel: [   20.902940]  [<ffffffffa0bc07a7>] ? firegl_open+0x2e7/0x320 [fglrx]
Jan  5 20:59:37 Houston kernel: [   20.902960]  [<ffffffffa0bb0b17>] ? ip_firegl_open+0x17/0x20 [fglrx]
Jan  5 20:59:37 Houston kernel: [   20.902979]  [<ffffffffa0bb0145>] ? firegl_stub_open+0xa5/0x120 [fglrx]
Jan  5 20:59:37 Houston kernel: [   20.902982]  [<ffffffff8118652f>] ? chrdev_open+0xaf/0x1a0
Jan  5 20:59:37 Houston kernel: [   20.902985]  [<ffffffff811803df>] ? __dentry_open+0x21f/0x330
Jan  5 20:59:37 Houston kernel: [   20.902987]  [<ffffffff81186480>] ? cdev_put+0x30/0x30
Jan  5 20:59:37 Houston kernel: [   20.902990]  [<ffffffff8118052a>] ? vfs_open+0x3a/0x40
Jan  5 20:59:37 Houston kernel: [   20.902992]  [<ffffffff811814d8>] ? nameidata_to_filp+0x58/0xb0
Jan  5 20:59:37 Houston kernel: [   20.902994]  [<ffffffff8118fe0f>] ? do_last+0x49f/0xa10
Jan  5 20:59:37 Houston kernel: [   20.902997]  [<ffffffff812ecacc>] ? apparmor_file_alloc_security+0x2c/0x60
Jan  5 20:59:37 Houston kernel: [   20.902999]  [<ffffffff81191669>] ? path_openat+0xd9/0x430
Jan  5 20:59:37 Houston kernel: [   20.903020]  [<ffffffffa0bb2696>] ? KCL_SPINLOCK_STATIC_Release+0x16/0x20 [fglrx]
Jan  5 20:59:37 Houston kernel: [   20.903045]  [<ffffffffa0bb8f83>] ? drm_free+0xf3/0x180 [fglrx]
Jan  5 20:59:37 Houston kernel: [   20.903070]  [<ffffffffa0bbeb5d>] ? firegl_release_helper+0x3dd/0x6c0 [fglrx]
Jan  5 20:59:37 Houston kernel: [   20.903072]  [<ffffffff81191ae1>] ? do_filp_open+0x41/0xa0
Jan  5 20:59:37 Houston kernel: [   20.903075]  [<ffffffff8119ec06>] ? alloc_fd+0xc6/0x110
Jan  5 20:59:37 Houston kernel: [   20.903076]  [<ffffffff81181625>] ? do_sys_open+0xf5/0x230
Jan  5 20:59:37 Houston kernel: [   20.903078]  [<ffffffff81181781>] ? sys_open+0x21/0x30
Jan  5 20:59:37 Houston kernel: [   20.903082]  [<ffffffff8168b969>] ? system_call_fastpath+0x16/0x1b
Jan  5 20:59:37 Houston kernel: [   20.903083] ---[ end trace 225b491b77a00de6 ]---
Jan  5 20:59:37 Houston kernel: [   20.903112] fglrx_pci 0000:01:00.0: irq 55 for MSI/MSI-X
Jan  5 20:59:37 Houston kernel: [   20.903122] fglrx_pci 0000:01:00.0: irq 56 for MSI/MSI-X
Jan  5 20:59:37 Houston kernel: [   20.903130] ------------[ cut here ]------------
Jan  5 20:59:37 Houston kernel: [   20.903133] WARNING: at /build/buildd/linux-3.5.0/fs/sysfs/dir.c:529 sysfs_add_one+0xd4/0x100()
Jan  5 20:59:37 Houston kernel: [   20.903134] Hardware name: HP Pavilion dv6 Notebook PC
Jan  5 20:59:37 Houston kernel: [   20.903135] sysfs: cannot create duplicate filename '/devices/pci0000:00/0000:00:01.0/0000:01:00.0/msi_irqs'
Jan  5 20:59:37 Houston kernel: [   20.903136] Modules linked in: fglrx(PO) amd_iommu_v2 parport_pc ppdev snd_hda_codec_hdmi rfcomm bnep snd_hda_codec_idt hp_wmi sparse_keymap binfmt_misc joydev coretemp kvm ghash_clmulni_intel aesni_intel cryptd aes_x86_64 lib80211_crypt_tkip snd_hda_intel snd_hda_codec snd_hwdep snd_pcm snd_seq_midi snd_rawmidi hid_generic wmi snd_seq_midi_event snd_seq snd_timer snd_seq_device uvcvideo videobuf2_core videodev videobuf2_vmalloc videobuf2_memops usbhid mac_hid snd hid microcode wl(PO) btusb hp_accel i915 bluetooth psmouse lis3lv02d input_polldev serio_raw drm_kms_helper lp lib80211 parport drm soundcore snd_page_alloc lpc_ich mei rts_pstor(C) i2c_algo_bit video r8169 [last unloaded: amd_iommu_v2]
Jan  5 20:59:37 Houston kernel: [   20.903163] Pid: 1253, comm: Xorg Tainted: P        WC O 3.5.0-21-generic #32-Ubuntu
Jan  5 20:59:37 Houston kernel: [   20.903164] Call Trace:
Jan  5 20:59:37 Houston kernel: [   20.903167]  [<ffffffff81051c1f>] warn_slowpath_common+0x7f/0xc0
Jan  5 20:59:37 Houston kernel: [   20.903169]  [<ffffffff81051d16>] warn_slowpath_fmt+0x46/0x50
Jan  5 20:59:37 Houston kernel: [   20.903172]  [<ffffffff81331d45>] ? strlcat+0x65/0x90
Jan  5 20:59:37 Houston kernel: [   20.903174]  [<ffffffff811f2cd4>] sysfs_add_one+0xd4/0x100
Jan  5 20:59:37 Houston kernel: [   20.903176]  [<ffffffff811f2ef8>] create_dir+0x78/0xd0
Jan  5 20:59:37 Houston kernel: [   20.903179]  [<ffffffff81337f27>] ? kvasprintf+0x57/0x90
Jan  5 20:59:37 Houston kernel: [   20.903181]  [<ffffffff811f3286>] sysfs_create_dir+0x86/0xe0
Jan  5 20:59:37 Houston kernel: [   20.903184]  [<ffffffff8132b33c>] kobject_add_internal+0x9c/0x220
Jan  5 20:59:37 Houston kernel: [   20.903186]  [<ffffffff8132b888>] ? kobject_set_name+0x38/0x40
Jan  5 20:59:37 Houston kernel: [   20.903189]  [<ffffffff8132b506>] kset_register+0x46/0x70
Jan  5 20:59:37 Houston kernel: [   20.903191]  [<ffffffff8132b906>] kset_create_and_add+0x76/0xc0
Jan  5 20:59:37 Houston kernel: [   20.903194]  [<ffffffff8136bf8e>] populate_msi_sysfs+0x2e/0x110
Jan  5 20:59:37 Houston kernel: [   20.903196]  [<ffffffff8136c4f3>] pci_enable_msi_block+0x1d3/0x2b0
Jan  5 20:59:37 Houston kernel: [   20.903218]  [<ffffffffa0bb3b63>] KCL_RequestMSI+0x13/0x20 [fglrx]
Jan  5 20:59:37 Houston kernel: [   20.903246]  [<ffffffffa0bd3c8f>] IRQMGR_initialize+0x24f/0x380 [fglrx]
Jan  5 20:59:37 Houston kernel: [   20.903274]  [<ffffffffa0bd39e7>] ? IRQMGR_alloc_context+0xb7/0x110 [fglrx]
Jan  5 20:59:37 Houston kernel: [   20.903302]  [<ffffffffa0bd2c2e>] ? irqmgr_wrap_initialize+0x1e/0xb0 [fglrx]
Jan  5 20:59:37 Houston kernel: [   20.903330]  [<ffffffffa0bd3885>] ? firegl_irqmgr_init+0x55/0x100 [fglrx]
Jan  5 20:59:37 Houston kernel: [   20.903359]  [<ffffffffa0be4486>] ? hal_init_gpu+0x1d6/0x4b0 [fglrx]
Jan  5 20:59:37 Houston kernel: [   20.903385]  [<ffffffffa0bc07a7>] ? firegl_open+0x2e7/0x320 [fglrx]
Jan  5 20:59:37 Houston kernel: [   20.903404]  [<ffffffffa0bb0b17>] ? ip_firegl_open+0x17/0x20 [fglrx]
Jan  5 20:59:37 Houston kernel: [   20.903423]  [<ffffffffa0bb0145>] ? firegl_stub_open+0xa5/0x120 [fglrx]
Jan  5 20:59:37 Houston kernel: [   20.903426]  [<ffffffff8118652f>] ? chrdev_open+0xaf/0x1a0
Jan  5 20:59:37 Houston kernel: [   20.903429]  [<ffffffff811803df>] ? __dentry_open+0x21f/0x330
Jan  5 20:59:37 Houston kernel: [   20.903431]  [<ffffffff81186480>] ? cdev_put+0x30/0x30
Jan  5 20:59:37 Houston kernel: [   20.903433]  [<ffffffff8118052a>] ? vfs_open+0x3a/0x40
Jan  5 20:59:37 Houston kernel: [   20.903435]  [<ffffffff811814d8>] ? nameidata_to_filp+0x58/0xb0
Jan  5 20:59:37 Houston kernel: [   20.903436]  [<ffffffff8118fe0f>] ? do_last+0x49f/0xa10
Jan  5 20:59:37 Houston kernel: [   20.903439]  [<ffffffff812ecacc>] ? apparmor_file_alloc_security+0x2c/0x60
Jan  5 20:59:37 Houston kernel: [   20.903441]  [<ffffffff81191669>] ? path_openat+0xd9/0x430
Jan  5 20:59:37 Houston kernel: [   20.903461]  [<ffffffffa0bb2696>] ? KCL_SPINLOCK_STATIC_Release+0x16/0x20 [fglrx]
Jan  5 20:59:37 Houston kernel: [   20.903485]  [<ffffffffa0bb8f83>] ? drm_free+0xf3/0x180 [fglrx]
Jan  5 20:59:37 Houston kernel: [   20.903510]  [<ffffffffa0bbeb5d>] ? firegl_release_helper+0x3dd/0x6c0 [fglrx]
Jan  5 20:59:37 Houston kernel: [   20.903513]  [<ffffffff81191ae1>] ? do_filp_open+0x41/0xa0
Jan  5 20:59:37 Houston kernel: [   20.903515]  [<ffffffff8119ec06>] ? alloc_fd+0xc6/0x110
Jan  5 20:59:37 Houston kernel: [   20.903516]  [<ffffffff81181625>] ? do_sys_open+0xf5/0x230
Jan  5 20:59:37 Houston kernel: [   20.903518]  [<ffffffff81181781>] ? sys_open+0x21/0x30
Jan  5 20:59:37 Houston kernel: [   20.903521]  [<ffffffff8168b969>] ? system_call_fastpath+0x16/0x1b
Jan  5 20:59:37 Houston kernel: [   20.903522] ---[ end trace 225b491b77a00de7 ]---
Jan  5 20:59:37 Houston kernel: [   20.903524] ------------[ cut here ]------------
Jan  5 20:59:37 Houston kernel: [   20.903526] WARNING: at /build/buildd/linux-3.5.0/lib/kobject.c:196 kobject_add_internal+0x204/0x220()
Jan  5 20:59:37 Houston kernel: [   20.903527] Hardware name: HP Pavilion dv6 Notebook PC
Jan  5 20:59:37 Houston kernel: [   20.903528] kobject_add_internal failed for msi_irqs with -EEXIST, don't try to register things with the same name in the same directory.
Jan  5 20:59:37 Houston kernel: [   20.903529] Modules linked in: fglrx(PO) amd_iommu_v2 parport_pc ppdev snd_hda_codec_hdmi rfcomm bnep snd_hda_codec_idt hp_wmi sparse_keymap binfmt_misc joydev coretemp kvm ghash_clmulni_intel aesni_intel cryptd aes_x86_64 lib80211_crypt_tkip snd_hda_intel snd_hda_codec snd_hwdep snd_pcm snd_seq_midi snd_rawmidi hid_generic wmi snd_seq_midi_event snd_seq snd_timer snd_seq_device uvcvideo videobuf2_core videodev videobuf2_vmalloc videobuf2_memops usbhid mac_hid snd hid microcode wl(PO) btusb hp_accel i915 bluetooth psmouse lis3lv02d input_polldev serio_raw drm_kms_helper lp lib80211 parport drm soundcore snd_page_alloc lpc_ich mei rts_pstor(C) i2c_algo_bit video r8169 [last unloaded: amd_iommu_v2]
Jan  5 20:59:37 Houston kernel: [   20.903556] Pid: 1253, comm: Xorg Tainted: P        WC O 3.5.0-21-generic #32-Ubuntu
Jan  5 20:59:37 Houston kernel: [   20.903557] Call Trace:
Jan  5 20:59:37 Houston kernel: [   20.903559]  [<ffffffff81051c1f>] warn_slowpath_common+0x7f/0xc0
Jan  5 20:59:37 Houston kernel: [   20.903562]  [<ffffffff81337f27>] ? kvasprintf+0x57/0x90
Jan  5 20:59:37 Houston kernel: [   20.903564]  [<ffffffff81051d16>] warn_slowpath_fmt+0x46/0x50
Jan  5 20:59:37 Houston kernel: [   20.903566]  [<ffffffff8132b4a4>] kobject_add_internal+0x204/0x220
Jan  5 20:59:37 Houston kernel: [   20.903569]  [<ffffffff8132b888>] ? kobject_set_name+0x38/0x40
Jan  5 20:59:37 Houston kernel: [   20.903571]  [<ffffffff8132b506>] kset_register+0x46/0x70
Jan  5 20:59:37 Houston kernel: [   20.903573]  [<ffffffff8132b906>] kset_create_and_add+0x76/0xc0
Jan  5 20:59:37 Houston kernel: [   20.903576]  [<ffffffff8136bf8e>] populate_msi_sysfs+0x2e/0x110
Jan  5 20:59:37 Houston kernel: [   20.903578]  [<ffffffff8136c4f3>] pci_enable_msi_block+0x1d3/0x2b0
Jan  5 20:59:37 Houston kernel: [   20.903600]  [<ffffffffa0bb3b63>] KCL_RequestMSI+0x13/0x20 [fglrx]
Jan  5 20:59:37 Houston kernel: [   20.903628]  [<ffffffffa0bd3c8f>] IRQMGR_initialize+0x24f/0x380 [fglrx]
Jan  5 20:59:37 Houston kernel: [   20.903656]  [<ffffffffa0bd39e7>] ? IRQMGR_alloc_context+0xb7/0x110 [fglrx]
Jan  5 20:59:37 Houston kernel: [   20.903683]  [<ffffffffa0bd2c2e>] ? irqmgr_wrap_initialize+0x1e/0xb0 [fglrx]
Jan  5 20:59:37 Houston kernel: [   20.903711]  [<ffffffffa0bd3885>] ? firegl_irqmgr_init+0x55/0x100 [fglrx]
Jan  5 20:59:37 Houston kernel: [   20.903740]  [<ffffffffa0be4486>] ? hal_init_gpu+0x1d6/0x4b0 [fglrx]
Jan  5 20:59:37 Houston kernel: [   20.903766]  [<ffffffffa0bc07a7>] ? firegl_open+0x2e7/0x320 [fglrx]
Jan  5 20:59:37 Houston kernel: [   20.903785]  [<ffffffffa0bb0b17>] ? ip_firegl_open+0x17/0x20 [fglrx]
Jan  5 20:59:37 Houston kernel: [   20.903804]  [<ffffffffa0bb0145>] ? firegl_stub_open+0xa5/0x120 [fglrx]
Jan  5 20:59:37 Houston kernel: [   20.903806]  [<ffffffff8118652f>] ? chrdev_open+0xaf/0x1a0
Jan  5 20:59:37 Houston kernel: [   20.903809]  [<ffffffff811803df>] ? __dentry_open+0x21f/0x330
Jan  5 20:59:37 Houston kernel: [   20.903811]  [<ffffffff81186480>] ? cdev_put+0x30/0x30
Jan  5 20:59:37 Houston kernel: [   20.903814]  [<ffffffff8118052a>] ? vfs_open+0x3a/0x40
Jan  5 20:59:37 Houston kernel: [   20.903815]  [<ffffffff811814d8>] ? nameidata_to_filp+0x58/0xb0
Jan  5 20:59:37 Houston kernel: [   20.903817]  [<ffffffff8118fe0f>] ? do_last+0x49f/0xa10
Jan  5 20:59:37 Houston kernel: [   20.903819]  [<ffffffff812ecacc>] ? apparmor_file_alloc_security+0x2c/0x60
Jan  5 20:59:37 Houston kernel: [   20.903821]  [<ffffffff81191669>] ? path_openat+0xd9/0x430
Jan  5 20:59:37 Houston kernel: [   20.903842]  [<ffffffffa0bb2696>] ? KCL_SPINLOCK_STATIC_Release+0x16/0x20 [fglrx]
Jan  5 20:59:37 Houston kernel: [   20.903866]  [<ffffffffa0bb8f83>] ? drm_free+0xf3/0x180 [fglrx]
Jan  5 20:59:37 Houston kernel: [   20.903891]  [<ffffffffa0bbeb5d>] ? firegl_release_helper+0x3dd/0x6c0 [fglrx]
Jan  5 20:59:37 Houston kernel: [   20.903893]  [<ffffffff81191ae1>] ? do_filp_open+0x41/0xa0
Jan  5 20:59:37 Houston kernel: [   20.903895]  [<ffffffff8119ec06>] ? alloc_fd+0xc6/0x110
Jan  5 20:59:37 Houston kernel: [   20.903897]  [<ffffffff81181625>] ? do_sys_open+0xf5/0x230
Jan  5 20:59:37 Houston kernel: [   20.903899]  [<ffffffff81181781>] ? sys_open+0x21/0x30
Jan  5 20:59:37 Houston kernel: [   20.903901]  [<ffffffff8168b969>] ? system_call_fastpath+0x16/0x1b
Jan  5 20:59:37 Houston kernel: [   20.903903] ---[ end trace 225b491b77a00de8 ]---
Jan  5 20:59:37 Houston kernel: [   20.903910] [fglrx] Could not enable MSI; System prevented initialization
Jan  5 20:59:37 Houston kernel: [   20.904267] [fglrx] Firegl kernel thread PID: 1396
Jan  5 20:59:37 Houston kernel: [   20.904336] [fglrx] Firegl kernel thread PID: 1397
Jan  5 20:59:37 Houston kernel: [   20.904402] [fglrx] Firegl kernel thread PID: 1398
Jan  5 20:59:37 Houston kernel: [   20.904450] genirq: Flags mismatch irq 54. 00000080 (fglrx[0]@PCI:1:0:0) vs. 00000820 ( \C2tP\88\FF\FF@PCI:1:0:0)
Jan  5 20:59:37 Houston kernel: [   20.904452] [fglrx:irqmgr_install_interrupt_handler] *ERROR* unable to install interrupt handler
Jan  5 20:59:37 Houston kernel: [   20.904454] [fglrx:irqmgr_wrap_initialize] *ERROR* IRQMGR fail to install interrupt handler! 
Jan  5 20:59:37 Houston kernel: [   20.913447] [fglrx:firegl_pplib_init_powerplay] *ERROR* PPLIB: PP_Initialize failed. 
Jan  5 20:59:37 Houston kernel: [   20.913466] [fglrx] Gart USWC size:1280 M.
Jan  5 20:59:37 Houston kernel: [   20.913469] [fglrx] Gart cacheable size:508 M.
Jan  5 20:59:37 Houston kernel: [   20.913474] [fglrx] Reserved FB block: Shared offset:0, size:1000000 
Jan  5 20:59:37 Houston kernel: [   20.913476] [fglrx] Reserved FB block: Unshared offset:f8fc000, size:404000 
Jan  5 20:59:37 Houston kernel: [   20.913478] [fglrx] Reserved FB block: Unshared offset:3fff4000, size:c000 
Jan  5 20:59:39 Houston kernel: [   22.760923] [fglrx] module unloaded - fglrx 9.1.11 [Dec  2 2012]