Linux version 3.5.0-15-generic (root@tangerine) (gcc version 4.7.1 (Ubuntu/Linaro 4.7.1-9ubuntu2) ) #20~lp1006690v1 SMP Tue Sep 18 15:45:39 UTC 2012 (Ubuntu 3.5.0-15.20~lp1006690v1-generic 3.5.4) no sound at all. not even alsamixer sees any devices. and this fault in dmesg : [ 23.550249] snd_hda_intel 0000:00:1b.0: irq 43 for MSI/MSI-X [ 23.629710] BUG: unable to handle kernel NULL pointer dereference at 0000000000000460 [ 23.629834] IP: [] alc_auto_parse_customize_define+0x16/0x150 [snd_hda_codec_realtek] [ 23.629922] PGD 12f422067 PUD 12f423067 PMD 0 [ 23.629988] Oops: 0000 [#1] SMP [ 23.630040] CPU 0 [ 23.630060] Modules linked in: snd_hda_codec_realtek snd_hda_intel(+) joydev uvcvideo snd_hda_codec snd_hwdep i915 videobuf2_core snd_pcm snd_seq_midi snd_rawmidi arc4 snd_seq_midi_event snd_seq videodev brcmsmac videobuf2_vmalloc snd_timer videobuf2_memops mac80211 snd_seq_device drm_kms_helper brcmutil snd kvm_intel kvm psmouse soundcore cfg80211 drm wmi snd_page_alloc serio_raw cordic bcma microcode lpc_ich i2c_algo_bit mac_hid video intel_ips mei coretemp atl1c [ 23.630718] [ 23.630730] Pid: 359, comm: modprobe Not tainted 3.5.0-15-generic #20~lp1006690v1 Acer Aspire xxxx/JV10_CS [ 23.630828] RIP: 0010:[] [] alc_auto_parse_customize_define+0x16/0x150 [snd_hda_codec_realtek] [ 23.630926] RSP: 0018:ffff88012f52fb48 EFLAGS: 00010292 [ 23.630972] RAX: ffffffffa043e950 RBX: 0000000000000000 RCX: 0000000000000000 [ 23.631030] RDX: 0000000000000007 RSI: 0000000000000000 RDI: ffff88012fbae000 [ 23.631087] RBP: ffff88012f52fb58 R08: ffff880137c16740 R09: ffff88012de65d20 [ 23.631143] R10: ffffea0004b67b40 R11: ffffffff8106ce24 R12: ffff88012fbae000 [ 23.631199] R13: ffff88012fbae000 R14: 00000000ffffffff R15: ffffffffa0444000 [ 23.631256] FS: 00007f124fb85700(0000) GS:ffff880137c00000(0000) knlGS:0000000000000000 [ 23.631321] CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b [ 23.631368] CR2: 0000000000000460 CR3: 000000012fbe3000 CR4: 00000000000007f0 [ 23.631425] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 23.631482] DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400 [ 23.631539] Process modprobe (pid: 359, threadinfo ffff88012f52e000, task ffff88012d4e4500) [ 23.631603] Stack: [ 23.634055] ffff88012fbae000 0000000000000001 ffff88012f52fb88 ffffffffa043e96a [ 23.636552] ffff88012f52fb88 ffffffffa0442088 0000000000000001 ffff88012fbae000 [ 23.639081] ffff88012f52fbf8 ffffffffa03fc456 000288012f52fbf8 2d6164682d646e73 [ 23.641595] Call Trace: [ 23.644069] [] patch_alc269+0x1a/0x2d0 [snd_hda_codec_realtek] [ 23.646572] [] snd_hda_codec_configure+0x146/0x440 [snd_hda_codec] [ 23.649087] [] azx_probe_continue+0x297/0x37c [snd_hda_intel] [ 23.651605] [] ? azx_get_response+0x280/0x280 [snd_hda_intel] [ 23.654124] [] ? azx_irq_pending_work+0x150/0x150 [snd_hda_intel] [ 23.656642] [] ? azx_dev_free+0x20/0x20 [snd_hda_intel] [ 23.659182] [] ? azx_resume+0x120/0x120 [snd_hda_intel] [ 23.661720] [] ? azx_init_chip+0x290/0x290 [snd_hda_intel] [ 23.664241] [] azx_probe+0x638/0x692 [snd_hda_intel] [ 23.666781] [] local_pci_probe+0x5c/0xd0 [ 23.669294] [] pci_device_probe+0x121/0x130 [ 23.671799] [] driver_probe_device+0x7e/0x220 [ 23.674293] [] __driver_attach+0xab/0xb0 [ 23.676792] [] ? driver_probe_device+0x220/0x220 [ 23.679306] [] bus_for_each_dev+0x55/0x90 [ 23.681821] [] ? 0xffffffffa042ffff [ 23.684321] [] driver_attach+0x1e/0x20 [ 23.686811] [] bus_add_driver+0x198/0x270 [ 23.689306] [] ? 0xffffffffa042ffff [ 23.691796] [] driver_register+0x77/0x150 [ 23.694272] [] ? 0xffffffffa042ffff [ 23.696710] [] __pci_register_driver+0x5f/0xe0 [ 23.699127] [] ? 0xffffffffa042ffff [ 23.701552] [] azx_driver_init+0x1e/0x1000 [snd_hda_intel] [ 23.703983] [] do_one_initcall+0x12a/0x180 [ 23.706334] [] sys_init_module+0xc2/0x230 [ 23.708626] [] system_call_fastpath+0x1a/0x1f [ 23.710840] Code: ff ff 31 c0 90 e9 dc fe ff ff 66 66 2e 0f 1f 84 00 00 00 00 00 55 48 89 e5 41 54 53 66 66 66 66 90 48 8b 9f c0 00 00 00 49 89 fc <0f> b6 8b 60 04 00 00 83 c9 01 f6 c1 10 88 8b 60 04 00 00 74 5d [ 23.716165] RIP [] alc_auto_parse_customize_define+0x16/0x150 [snd_hda_codec_realtek] [ 23.718602] RSP [ 23.720965] CR2: 0000000000000460 [ 23.723420] ---[ end trace 3b543704a6293369 ]--- It seems that the patch can not be reverted in easy way.