cpuidle / ACPI: recover percpu ACPI processor cstate
authorAlex Shi <alex.shi@intel.com>
Mon, 1 Apr 2013 23:56:54 +0000 (01:56 +0200)
committerRafael J. Wysocki <rafael.j.wysocki@intel.com>
Tue, 2 Apr 2013 13:31:28 +0000 (15:31 +0200)
commit6240a10dc55a954ce05a86d2f4bc27e473b6352c
tree22f72ecfd27ba4af6714c82aadac271cadec9777
parentb34bb1ee71158d5b0f9028fb98afd026202bcfe9
cpuidle / ACPI: recover percpu ACPI processor cstate

Commit ac3ebafa81af76d6 "ACPI / idle: remove usage of the statedata"
changed the percpu processor cstate to a unified cstate in ACPI idle.
That caused all our NHM boxes to boot hang or panic.

2178751 Task dump for CPU 1:
2178752 swapper/1       R  running task     6736     0      1 0x00000000
2178753  ffff8801e8029dc8 ffffffff8101cf96 ffff8801e8029e28 ffffffff813d294b
2178754  0000000000000f99 0000000000000003 00000000003cf654 0000000025c17d03
2178755  ffff8801e8029e38 ffff8801e74fc000 00000002590dc5c4 ffffffff8163cdb0
2178756 Call Trace:
2178757  [<ffffffff8101cf96>] ? acpi_processor_ffh_cstate_enter+0x2d/0x2f
2178758  [<ffffffff813d294b>] acpi_idle_enter_bm+0x1b1/0x236
2178759  [<ffffffff8163cdb0>] ? disable_cpuidle+0x10/0x10
2178760  [<ffffffff8163cdc2>] cpuidle_enter+0x12/0x14
2178761  [<ffffffff8163d286>] cpuidle_wrap_enter+0x2f/0x6d
2178762  [<ffffffff8163d2d4>] cpuidle_enter_tk+0x10/0x12
2178763  [<ffffffff8163cdd6>] cpuidle_enter_state+0x12/0x3a
2178764  [<ffffffff8163d4a7>] cpuidle_idle_call+0xe8/0x161
2178765  [<ffffffff81008d99>] cpu_idle+0x5e/0xa4
2178766  [<ffffffff8174c6c1>] start_secondary+0x1a9/0x1ad
2178767 Task dump for CPU 2:

In fact, the ACPI idle is based on the assumption of difference percpu
cstate structures that are necessary for the implementation to work
cprrectly.  A unique acpi_processor_cx is not sifficient by far.

This patch is just a quick fix re-introducing the percpu cstates.

If someone really wants to unify the ACPI cstates, please make sure
that the whole software infrastructure is changed and take hardware
as well as many different kinds of BIOS settings into account.

[rjw: Changelog]
Reported-by: LKP project <lkp@linux.intel.com>
Reported-by: Xie ChanglongX <changlongx.xie@intel.com>
Tested-by: Yinghai Lu <yinghai@kernel.org>
Signed-off-by: Alex Shi <alex.shi@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
drivers/acpi/processor_idle.c