forked from Minki/linux
785a12afdb
Currently, we use the opal call opal_slw_set_reg() to inform the
Sleep-Winkle Engine (SLW) to restore the contents of some of the
Hypervisor state on wakeup from deep idle states that lose full
hypervisor context (characterized by the flag
OPAL_PM_LOSE_FULL_CONTEXT).
However, the current code has a bug in that if opal_slw_set_reg()
fails, we don't disable the use of these deep states (winkle on
POWER8, stop4 onwards on POWER9).
This patch fixes this bug by ensuring that if programing the
sleep-winkle engine to restore the hypervisor states in
pnv_save_sprs_for_deep_states() fails, then we exclude such states by
clearing the OPAL_PM_LOSE_FULL_CONTEXT flag from
supported_cpuidle_states. As a result POWER8 will be prevented from
using winkle for CPU-Hotplug, and POWER9 will put the offlined CPUs to
the default stop state when available.
Further, we ensure in the initialization of the cpuidle-powernv driver
to only include those states whose flags are present in
supported_cpuidle_states, thereby skipping OPAL_PM_LOSE_FULL_CONTEXT
states when they have been disabled due to stop-api failure.
Fixes:
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.. | ||
8xx | ||
40x | ||
44x | ||
52xx | ||
82xx | ||
83xx | ||
85xx | ||
86xx | ||
512x | ||
amigaone | ||
cell | ||
chrp | ||
embedded6xx | ||
maple | ||
pasemi | ||
powermac | ||
powernv | ||
ps3 | ||
pseries | ||
fsl_uli1575.c | ||
Kconfig | ||
Kconfig.cputype | ||
Makefile |