[PATCH v2 0/2] WFE for long delays

Julien Thierry julien.thierry at arm.com
Thu Aug 17 01:39:18 PDT 2017


It was pointed out that there are some windows where the event stream might not
be configured, meaning we cannot safely use WFE (e.g. when using PSCI
CPU_SUSPEND for idle, PSCI might reset CPU state).

The first patch provide a function to check whether the task is in state where
it can expect events from the event stream.

Second patch actually makes use of WFE in delays.

Changes since v1:
- Keep track of event stream state
- Do not use WFE when event stream might be misconfigured

Julien Thierry (2):
  arm_arch_timer: Expose event stream status
  arm64: use WFE for long delays

 arch/arm/include/asm/arch_timer.h    |  1 +
 arch/arm64/include/asm/arch_timer.h  |  1 +
 arch/arm64/lib/delay.c               | 25 ++++++++++++++++++++-----
 drivers/clocksource/arm_arch_timer.c | 32 ++++++++++++++++++++++++++++++--
 include/asm-generic/delay.h          |  9 +++++++--
 include/clocksource/arm_arch_timer.h |  6 ++++++
 6 files changed, 65 insertions(+), 9 deletions(-)

--
1.9.1



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