[PATCH v3 0/2] WFE for long delays
Julien Thierry
julien.thierry at arm.com
Fri Sep 29 03:52:28 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
Changes since v2:
- Use cpumask to track event stream state instead of percpu variable
- Tidy a bit code in arm64/lib/delay
- Do not factor asm-generic/delay code
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 | 23 +++++++++++++++++++----
drivers/clocksource/arm_arch_timer.c | 20 ++++++++++++++++++--
include/clocksource/arm_arch_timer.h | 10 +++++++++-
5 files changed, 48 insertions(+), 7 deletions(-)
--
1.9.1
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