[    0.373330] ------------[ cut here ]------------
[    0.373549] WARNING: CPU: 0 PID: 0 at kernel/time/tick-broadcast.c:668 tick_broadcast_oneshot_control+0x9e/0x16b()
[    0.373966] Modules linked in:
[    0.374196] CPU: 0 PID: 0 Comm: swapper/0 Not tainted 3.13.0-gentoo-r1 #1
[    0.374409] Hardware name: MSI MS-7640/890FXA-GD70 (MS-7640)  , BIOS V1.15 10/31/2012
[    0.374624]  0000000000000009 ffffffff81e01e28 ffffffff8166f379 00000000000000df
[    0.374924]  0000000000000000 ffffffff81e01e68 ffffffff81030a59 0000000000000040
[    0.375223]  ffffffff81074f4d ffff880437c0cc00 0000000000000000 0000000000000000
[    0.375525] Call Trace:
[    0.375738]  [<ffffffff8166f379>] dump_stack+0x46/0x58
[    0.375951]  [<ffffffff81030a59>] warn_slowpath_common+0x77/0x91
[    0.376166]  [<ffffffff81074f4d>] ? tick_broadcast_oneshot_control+0x9e/0x16b
[    0.376378]  [<ffffffff81030a88>] warn_slowpath_null+0x15/0x17
[    0.376591]  [<ffffffff81074f4d>] tick_broadcast_oneshot_control+0x9e/0x16b
[    0.376805]  [<ffffffff81073b10>] clockevents_notify+0x4d/0x1c6
[    0.377020]  [<ffffffff81008b93>] amd_e400_idle+0xa9/0xc7
[    0.377231]  [<ffffffff810090a0>] arch_cpu_idle+0x13/0x18
[    0.377445]  [<ffffffff810662c6>] cpu_startup_entry+0xf6/0x174
[    0.377660]  [<ffffffff81667ad9>] rest_init+0x6d/0x6f
[    0.377872]  [<ffffffff81ea1cf8>] start_kernel+0x3b4/0x3c1
[    0.378085]  [<ffffffff81ea174c>] ? repair_env_string+0x5a/0x5a
[    0.378301]  [<ffffffff81ea1481>] x86_64_start_reservations+0x2a/0x2c
[    0.378512]  [<ffffffff81ea1550>] x86_64_start_kernel+0xcd/0xd1
[    0.378726] ---[ end trace d6066f60a7a5115f ]---


This error was not present on 3.12.8 and previous. The kernel .config is the same (almost, some network filter options were added, but that doesn't seem related in any way).

The kernel recovers and the system boots normally after a short delay. Only, sound is not available (i.e. no sound on my headphones) at all -- even though the volume controls are there...

I reverted to 3.12.8 for now...