Hi,
with these patches AM437x devices can use TWD/global timers.
At least TWD is now used as sched_clock() which gives better latency as seen
below. Keep in mind that while I ran cyclictest to have a feel for avg latency
this test was not against an RT kernel, so results should be taken with a
grain of salt.
Also, I'm not 100% sure clock rate is correct. According to TRM, this timer
should run as MPU_CLK/2 which would be 1GHz / 2 = 500MHz, but even though
I'm using dpll_mpu_m2_ck clock, it still shows as 1000MHz.
Are there any other tests I could/should run ? BTW, I boot-tested on AM4372
with and without 'nosmp' on cmdline.
pre-patch:
T: 0 ( 245) P:95 I:1000 C: 9995 Min: 24 Act: 31 Avg: 36 Max: 596
post-patch:
T: 0 ( 253) P:95 I:1000 C: 9995 Min: 10 Act: 12 Avg: 14 Max: 68
Changes since v1:
- Rebased on top of today's linux-next (c1a0c66f231d Add linux-next
specific files for 20150812)
Felipe Balbi (4):
Revert "ARM: 7655/1: smp_twd: make twd_local_timer_of_register() no-op
for nosmp"
arm: boot: dts: am4372: add ARM timers and SCU nodes
arm: omap2: Kconfig: select TWD and global timer on AM43xx devices
arm: omap2: board-generic: use omap4_local_timer_init for AM437x
arch/arm/boot/dts/am4372.dtsi | 21 +++++++++++++++++++++
arch/arm/kernel/smp_twd.c | 4 ----
arch/arm/mach-omap2/Kconfig | 3 +++
arch/arm/mach-omap2/board-generic.c | 2 +-
4 files changed, 25 insertions(+), 5 deletions(-)
--
2.5.0
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