With the two mentioned patches, and the Ubuntu Raring 3.8.0-16.26 kernel, I am no longer seeing the link train errors in dmesg when trying to use the second display. Instead, I am now getting a lot of traces in dmesg, all very similar to this one:
[ 506.787670] ------------[ cut here ]------------ [ 506.787700] WARNING: at /tmp/buildd/linux-3.8.0/drivers/gpu/drm/i915/intel_display.c:1028 intel_wait_for_pipe_off+0xe2/0x1a0 [i915]() [ 506.787703] Hardware name: [ 506.787704] pipe_off wait timed out [ 506.787705] Modules linked in: snd_hda_codec_hdmi snd_hda_codec_realtek pci_stub vboxpci(OF) vboxnetadp(OF) vboxnetflt(OF) vboxdrv(OF) parport_pc ppdev rfcomm bnep bluetooth binfmt_misc nls_iso8859_1 kvm_intel kvm ghash_clmulni_intel aesni_intel aes_x86_64 xts lrw gf128mul ablk_helper cryptd microcode joydev snd_hda_intel snd_usb_audio snd_hda_codec snd_usbmidi_lib snd_hwdep snd_pcm snd_page_alloc tpm_tis snd_seq_midi snd_seq_midi_event snd_rawmidi snd_seq snd_seq_device snd_timer lpc_ich i915 snd soundcore video drm_kms_helper mei drm i2c_algo_bit w83627ehf hwmon_vid mac_hid coretemp lp parport hid_generic usbhid hid usb_storage firewire_ohci firewire_core ahci crc_itu_t libahci e1000e [ 506.787750] Pid: 1700, comm: Xorg Tainted: GF W O 3.8.0-16-generic #26 [ 506.787752] Call Trace: [ 506.787759] [<ffffffff810587df>] warn_slowpath_common+0x7f/0xc0 [ 506.787762] [<ffffffff810588dc>] warn_slowpath_fmt+0x4c/0x50 [ 506.787777] [<ffffffffa0196d22>] intel_wait_for_pipe_off+0xe2/0x1a0 [i915] [ 506.787790] [<ffffffffa0196ef6>] intel_disable_pipe+0x116/0x190 [i915] [ 506.787801] [<ffffffffa019769b>] ironlake_crtc_disable+0xdb/0x880 [i915] [ 506.787816] [<ffffffffa010995c>] ? drm_mode_create+0x4c/0x80 [drm] [ 506.787830] [<ffffffffa019f34b>] intel_set_mode+0x36b/0xa30 [i915] [ 506.787844] [<ffffffffa01a0126>] intel_crtc_set_config+0x716/0x950 [i915] [ 506.787856] [<ffffffffa010bc21>] drm_mode_setcrtc+0x121/0x5a0 [drm] [ 506.787867] [<ffffffffa00fc559>] drm_ioctl+0x4e9/0x5b0 [drm] [ 506.787878] [<ffffffffa010bb00>] ? drm_mode_setplane+0x370/0x370 [drm] [ 506.787883] [<ffffffff811a5849>] do_vfs_ioctl+0x99/0x570 [ 506.787887] [<ffffffff811a5db1>] sys_ioctl+0x91/0xb0 [ 506.787892] [<ffffffff816d32dd>] system_call_fastpath+0x1a/0x1f [ 506.787894] ---[ end trace 383823ffb51e7397 ]---
With the two mentioned patches, and the Ubuntu Raring 3.8.0-16.26 kernel, I am no longer seeing the link train errors in dmesg when trying to use the second display. Instead, I am now getting a lot of traces in dmesg, all very similar to this one:
[ 506.787670] ------------[ cut here ]------------ linux-3. 8.0/drivers/ gpu/drm/ i915/intel_ display. c:1028 intel_wait_ for_pipe_ off+0xe2/ 0x1a0 [i915]() codec_realtek pci_stub vboxpci(OF) vboxnetadp(OF) vboxnetflt(OF) vboxdrv(OF) parport_pc ppdev rfcomm bnep bluetooth binfmt_misc nls_iso8859_1 kvm_intel kvm ghash_clmulni_intel aesni_intel aes_x86_64 xts lrw gf128mul ablk_helper cryptd microcode joydev snd_hda_intel snd_usb_audio snd_hda_codec snd_usbmidi_lib snd_hwdep snd_pcm snd_page_alloc tpm_tis snd_seq_midi snd_seq_midi_event snd_rawmidi snd_seq snd_seq_device snd_timer lpc_ich i915 snd soundcore video drm_kms_helper mei drm i2c_algo_bit w83627ehf hwmon_vid mac_hid coretemp lp parport hid_generic usbhid hid usb_storage firewire_ohci firewire_core ahci crc_itu_t libahci e1000e 7df>] warn_slowpath_ common+ 0x7f/0xc0 8dc>] warn_slowpath_ fmt+0x4c/ 0x50 d22>] intel_wait_ for_pipe_ off+0xe2/ 0x1a0 [i915] ef6>] intel_disable_ pipe+0x116/ 0x190 [i915] 69b>] ironlake_ crtc_disable+ 0xdb/0x880 [i915] 95c>] ? drm_mode_ create+ 0x4c/0x80 [drm] 34b>] intel_set_ mode+0x36b/ 0xa30 [i915] 126>] intel_crtc_ set_config+ 0x716/0x950 [i915] c21>] drm_mode_ setcrtc+ 0x121/0x5a0 [drm] 559>] drm_ioctl+ 0x4e9/0x5b0 [drm] b00>] ? drm_mode_ setplane+ 0x370/0x370 [drm] 849>] do_vfs_ ioctl+0x99/ 0x570 db1>] sys_ioctl+0x91/0xb0 2dd>] system_ call_fastpath+ 0x1a/0x1f
[ 506.787700] WARNING: at /tmp/buildd/
[ 506.787703] Hardware name:
[ 506.787704] pipe_off wait timed out
[ 506.787705] Modules linked in: snd_hda_codec_hdmi snd_hda_
[ 506.787750] Pid: 1700, comm: Xorg Tainted: GF W O 3.8.0-16-generic #26
[ 506.787752] Call Trace:
[ 506.787759] [<ffffffff81058
[ 506.787762] [<ffffffff81058
[ 506.787777] [<ffffffffa0196
[ 506.787790] [<ffffffffa0196
[ 506.787801] [<ffffffffa0197
[ 506.787816] [<ffffffffa0109
[ 506.787830] [<ffffffffa019f
[ 506.787844] [<ffffffffa01a0
[ 506.787856] [<ffffffffa010b
[ 506.787867] [<ffffffffa00fc
[ 506.787878] [<ffffffffa010b
[ 506.787883] [<ffffffff811a5
[ 506.787887] [<ffffffff811a5
[ 506.787892] [<ffffffff816d3
[ 506.787894] ---[ end trace 383823ffb51e7397 ]---