MIPS: OCTEON: Improve _machine_halt implementation.
authorDavid Daney <david.daney@cavium.com>
Fri, 24 May 2013 16:23:02 +0000 (16:23 +0000)
committerRalf Baechle <ralf@linux-mips.org>
Thu, 6 Jun 2013 14:11:26 +0000 (16:11 +0200)
commit38c3c0f6733bec1d1841915a9a82d2c324362686
treefe8d90c4b584519c00c41c66898656b38656a5b5
parent406b5ee22215554a37760b6fa807da6ad4d52f52
MIPS: OCTEON: Improve _machine_halt implementation.

As noted by Wladislav Wiebe:
   $ halt
   ..
   Sent SIGKILL to all processes
   Requesting system halt
   [66.729373] System halted.
   [66.733244]
   [66.734761] =====================================
   [66.739473] [ BUG: lock held at task exit time! ]
   [66.744188] 3.8.7-0-sampleversion-fct #49 Tainted: G           O
   [66.750202] -------------------------------------
   [66.754913] init/21479 is exiting with locks still held!
   [66.760234] 1 lock held by init/21479:
   [66.763990]  #0:  (reboot_mutex){+.+...}, at: [<ffffffff801776c8>] SyS_reboot+0xe0/0x218
   [66.772165]
   [66.772165] stack backtrace:
   [66.776532] Call Trace:
   [66.778992] [<ffffffff805780a8>] dump_stack+0x8/0x34
   [66.783972] [<ffffffff801618b0>] do_exit+0x610/0xa70
   [66.788948] [<ffffffff801777a8>] SyS_reboot+0x1c0/0x218
   [66.794186] [<ffffffff8013d6a4>] handle_sys64+0x44/0x64

This is an alternative fix to the one sent by Wladislav.  We kill the
watchdog for each CPU and then spin in WAIT with interrupts disabled.
This is the lowest power mode for the OCTEON.  If we were to spin with
interrupts enabled, we would get a continual stream of warning messages
and backtraces from the lockup detector, so I chose to disable
interrupts.

Signed-off-by: David Daney <david.daney@cavium.com>
Cc: Maxim Uvarov <muvarov@gmail.com>
Cc: Wladislav Wiebe <wladislav.kw@gmail.com>
Cc: linux-mips@linux-mips.org
Cc: David Daney <david.daney@cavium.com>
Patchwork: https://patchwork.linux-mips.org/patch/5324/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
arch/mips/cavium-octeon/setup.c