From mboxrd@z Thu Jan 1 00:00:00 1970 From: Benjamin Gaignard Subject: [PATCH v8 3/6] clocksource: stm32: increase min delta value Date: Tue, 14 Nov 2017 09:52:40 +0100 Message-ID: <1510649563-22975-4-git-send-email-benjamin.gaignard@linaro.org> References: <1510649563-22975-1-git-send-email-benjamin.gaignard@linaro.org> Return-path: In-Reply-To: <1510649563-22975-1-git-send-email-benjamin.gaignard-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org> Sender: devicetree-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: robh+dt-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org, mark.rutland-5wv7dgnIgG8@public.gmane.org, linux-I+IVW8TIWO2tmTQ+vhA3Yw@public.gmane.org, mcoquelin.stm32-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org, alexandre.torgue-qxv4g6HH51o@public.gmane.org, daniel.lezcano-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org, tglx-hfZtesqFncYOwBW4kG4KsQ@public.gmane.org, ludovic.barre-qxv4g6HH51o@public.gmane.org, julien.thierry-5wv7dgnIgG8@public.gmane.org, sudeep.holla-5wv7dgnIgG8@public.gmane.org, arnd-r2nGTMty4D4@public.gmane.org Cc: devicetree-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, Benjamin Gaignard List-Id: devicetree@vger.kernel.org The CPU is a CortexM4 @ 200MHZ and the clocks driving the timers are at 90MHZ with a min delta at 1 you could have an interrupt each 0.01 ms which is really to much. By increase it to 0x60 it give more time (around 1 ms) to CPU to handle the interrupt. Signed-off-by: Benjamin Gaignard --- drivers/clocksource/timer-stm32.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/drivers/clocksource/timer-stm32.c b/drivers/clocksource/timer-stm32.c index fc61fd1..ae41a19 100644 --- a/drivers/clocksource/timer-stm32.c +++ b/drivers/clocksource/timer-stm32.c @@ -36,6 +36,8 @@ #define TIM_EGR_UG BIT(0) +#define MIN_DELTA 0x60 + static int stm32_clock_event_shutdown(struct clock_event_device *evt) { struct timer_of *to = to_timer_of(evt); @@ -129,7 +131,7 @@ static int __init stm32_clockevent_init(struct device_node *node) writel_relaxed(0, timer_of_base(to) + TIM_SR); clockevents_config_and_register(&to->clkevt, - timer_of_period(to), 0x1, max_delta); + timer_of_period(to), MIN_DELTA, max_delta); pr_info("%pOF: STM32 clockevent driver initialized (%d bits)\n", node, bits); -- 2.7.4 -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org More majordomo info at http://vger.kernel.org/majordomo-info.html