Clearly a harder reboot is required, I will power the machine off and unplug it from the AC for a few minutes. A regular powercycle resulted in the following oops report:
ACPI: PCI Interrupt Link [LK2E] enabled at IRQ 47 ACPI: PCI Interrupt 0000:83:00.0[A] -> Link [LK2E] -> GSI 47 (level, high) -> IRQ 47 PCI: Setting latency timer of device 0000:83:00.0 to 64 ALSA sound/pci/hda/hda_intel.c:2022: chipset global capabilities = 0x3500 ALSA sound/pci/hda/hda_intel.c:754: codec_mask = 0x2 ALSA sound/pci/hda/hda_codec.c:3242: autoconfig: line_outs=4 (0xd/0xf/0xe/0x10/0x0) ALSA sound/pci/hda/hda_codec.c:3246: speaker_outs=0 (0x0/0x0/0x0/0x0/0x0) ALSA sound/pci/hda/hda_codec.c:3250: hp_outs=1 (0x11/0x0/0x0/0x0/0x0) ALSA sound/pci/hda/hda_codec.c:3251: mono: mono_out=0x0 ALSA sound/pci/hda/hda_codec.c:3259: inputs: mic=0x14, fmic=0x0, line=0x13, fline=0x0, cd=0x0, aux=0x0 ALSA sound/pci/hda/hda_codec.c:2336: BUG? (info->nid) Pid: 1, comm: swapper Not tainted 2.6.26-rc7-00240-gfae47c0 #1
Call Trace: [<ffffffff804668ed>] snd_hda_build_pcms+0x1fc/0x29c [<ffffffff804ec225>] azx_probe+0x7ed/0x7fd [<ffffffff804639b5>] azx_send_cmd+0x0/0x130 [<ffffffff80463ae5>] azx_get_response+0x0/0x207 [<ffffffff8046320a>] azx_attach_pcm_stream+0x0/0x1a0 [<ffffffff80462ed4>] azx_power_notify+0x0/0x51 [<ffffffff80324bd1>] pci_device_probe+0xa9/0xf6 [<ffffffff803b138a>] driver_probe_device+0xb5/0x159 [<ffffffff803b1474>] __driver_attach+0x46/0x6d [<ffffffff803b142e>] __driver_attach+0x0/0x6d [<ffffffff803b0c9e>] bus_for_each_dev+0x44/0x78 [<ffffffff803b0630>] bus_add_driver+0xac/0x1e6 [<ffffffff803b1638>] driver_register+0xa2/0x11f [<ffffffff80324e4a>] __pci_register_driver+0x4a/0x7c [<ffffffff80660b68>] alsa_card_azx_init+0x0/0x15 [<ffffffff80644656>] kernel_init+0x146/0x28b [<ffffffff8020cc08>] child_rip+0xa/0x12 [<ffffffff80644510>] kernel_init+0x0/0x28b [<ffffffff8020cbfe>] child_rip+0x0/0x12
ACPI: PCI interrupt for device 0000:83:00.0 disabled HDA Intel: probe of 0000:83:00.0 failed with error -22 ALSA device list: No soundcards found.
Regards, Tony V.