Am Dienstag, 29. November 2016, 19:14:52 CET schrieb Alexander Kochetkov: > The clock supplying the arm-global-timer on the rk3188 is coming from the > the cpu clock itself and thus changes its rate everytime cpufreq adjusts > the cpu frequency making this timer unsuitable as a stable clocksource > and sched clock. > > The rk3188, rk3288 and following socs share a separate timer block already > handled by the rockchip-timer driver. Therefore adapt this driver to also > be able to act as clocksource and sched clock on rk3188. > > In order to test clocksource you can run following commands and check > how much time it take in real. On rk3188 it take about ~45 seconds. > > cpufreq-set -f 1.6GHZ > date; sleep 60; date > > In order to use the patch you need to declare two timers in the dts > file. The first timer will be initialized as clockevent provider > and the second one as clocksource. The clockevent must be from > alive subsystem as it used as backup for the local timers at sleep > time. > > The patch does not break compatibility with older device tree files. > The older device tree files contain only one timer. The timer > will be initialized as clockevent, as expected. > > rk3288 (and probably anything newer) is irrelevant to this patch, > as it has the arch timer interface. This patch may be usefull > for Cortex-A9/A5 based parts. > > Signed-off-by: Alexander Kochetkov <al.kochet@xxxxxxxxx> [...] > @@ -120,13 +161,46 @@ static irqreturn_t rk_timer_interrupt(int irq, void > *dev_id) return IRQ_HANDLED; > } > > +static cycle_t rk_timer_clocksource_read(struct clocksource *cs) ^^ ../drivers/clocksource/rockchip_timer.c:164:8: error: unknown type name ‘cycle_t’ static cycle_t rk_timer_clocksource_read(struct clocksource *cs) looks like something in clocksources changed since november -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
