linux/arch/powerpc/platforms
Shreyas B. Prabhu 0eb13208aa powerpc/powernv: Restore LPCR with LPCR_PECE1 cleared
LPCR_PECE1 bit controls whether decrementer interrupts are allowed to
cause exit from power-saving mode. While waking up from winkle, restoring
LPCR with LPCR_PECE1 set (i.e Decrementer interrupts allowed) can cause
issue in the following scenario:

- All the threads in a core are offlined. The core enters deep winkle.
- Spurious interrupt wakes up a thread in the core. Here LPCR is restored
  with LPCR_PECE1 bit set.
- Since it was a spurious interrupt on a offline thread, the thread clears
  the interrupt and goes back to winkle.
- Here before the thread executes winkle and puts the core into deep winkle,
  if a decrementer interrupt occurs on any of the sibling threads in the core
  that thread wakes up.
- Since in offline loop we are flushing interrupt only in case of external
  interrupt, the decrementer interrupt does not get flushed. So at this stage
  the thread is stuck in this is loop of waking up at 0x100 due to decrementer
  interrupt, not flushing the interrupt as only external interrupts get flushed,
  entering winkle, waking up at 0x100 again.

Fix this by programming PORE to restore LPCR with LPCR_PECE1 bit
cleared when waking up from winkle.

Signed-off-by: Shreyas B. Prabhu <shreyas@linux.vnet.ibm.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2015-01-22 17:22:57 +11:00
..
8xx powerpc/8xx: Remove Kconfig symbol FADS 2014-11-07 18:10:46 -06:00
40x powerpc: make of_device_ids const 2014-09-25 23:14:46 +10:00
44x Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial 2014-12-12 10:08:06 -08:00
52xx Driver core patches for 3.19-rc1 2014-12-14 16:10:09 -08:00
82xx powerpc: platforms: 82xx: drop owner assignment from platform_drivers 2014-10-20 16:20:11 +02:00
83xx Driver core patches for 3.19-rc1 2014-12-14 16:10:09 -08:00
85xx Driver core patches for 3.19-rc1 2014-12-14 16:10:09 -08:00
86xx powerpc: make of_device_ids const 2014-09-25 23:14:46 +10:00
512x powerpc: Remove bootmem allocator 2014-11-10 09:59:25 +11:00
amigaone lib/scatterlist: make ARCH_HAS_SG_CHAIN an actual Kconfig 2014-08-08 15:57:26 -07:00
cell Driver core patches for 3.19-rc1 2014-12-14 16:10:09 -08:00
chrp powerpc: Convert power off logic to pm_power_off 2014-11-03 12:12:51 +11:00
embedded6xx powerpc/gamecube/wii: delete unneeded test before of_node_put 2014-11-10 09:59:35 +11:00
maple powerpc: Remove superfluous bootmem includes 2014-11-10 09:59:26 +11:00
pasemi powerpc: platforms: pasemi: drop owner assignment from platform_drivers 2014-10-20 16:20:12 +02:00
powermac powerpc: Remove more traces of bootmem 2014-11-19 21:41:51 +11:00
powernv powerpc/powernv: Restore LPCR with LPCR_PECE1 cleared 2015-01-22 17:22:57 +11:00
ps3 powerpc/mm: don't do tlbie for updatepp request with NO HPTE fault 2014-12-05 16:26:15 +11:00
pseries powerpc/kdump: Ignore failure in enabling big endian exception during crash 2014-12-29 15:44:53 +11:00
fsl_uli1575.c of/irq: Refactor interrupt-map parsing 2013-10-24 11:43:04 +01:00
Kconfig powerpc: Remove platforms/wsp and associated pieces 2014-06-11 16:35:38 +10:00
Kconfig.cputype Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mpe/linux 2014-10-11 20:34:00 -04:00
Makefile powerpc: Remove platforms/wsp and associated pieces 2014-06-11 16:35:38 +10:00