From: Benjamin Gaignard <benjamin.gaignard-QSEj5FYQhm4dnm+yROfE0A@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
<benjamin.gaignard-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org>
Subject: [PATCH v8 3/6] clocksource: stm32: increase min delta value
Date: Tue, 14 Nov 2017 09:52:40 +0100 [thread overview]
Message-ID: <1510649563-22975-4-git-send-email-benjamin.gaignard@linaro.org> (raw)
In-Reply-To: <1510649563-22975-1-git-send-email-benjamin.gaignard-QSEj5FYQhm4dnm+yROfE0A@public.gmane.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 <benjamin.gaignard-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org>
---
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
--
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next prev parent reply other threads:[~2017-11-14 8:52 UTC|newest]
Thread overview: 21+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-11-14 8:52 [PATCH v8 0/6] stm32 clocksource driver rework Benjamin Gaignard
[not found] ` <1510649563-22975-1-git-send-email-benjamin.gaignard-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org>
2017-11-14 8:52 ` [PATCH v8 1/6] clocksource: timer_of: rename timer_of_exit to timer_of_cleanup Benjamin Gaignard
2017-11-14 8:52 ` [PATCH v8 2/6] clocksource: stm32: convert driver to timer_of Benjamin Gaignard
2017-11-14 8:52 ` Benjamin Gaignard [this message]
2017-12-08 9:28 ` [PATCH v8 3/6] clocksource: stm32: increase min delta value Daniel Lezcano
2017-11-14 8:52 ` [PATCH v8 4/6] clocksource: stm32: only use 32 bits timers Benjamin Gaignard
[not found] ` <1510649563-22975-5-git-send-email-benjamin.gaignard-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org>
2017-12-07 15:27 ` Daniel Lezcano
2017-12-07 16:33 ` Benjamin Gaignard
2017-12-07 16:49 ` Daniel Lezcano
2017-12-07 20:36 ` Benjamin Gaignard
[not found] ` <CA+M3ks4KLy0VkJOSGR7tmefOT1rw9nrMsRQvwwK-YZQ7Gm7hQA-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2017-12-08 7:52 ` Daniel Lezcano
2017-12-08 8:34 ` Daniel Lezcano
[not found] ` <f22fd299-a742-1144-75d0-256a538af619-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org>
2017-12-08 9:25 ` Benjamin Gaignard
[not found] ` <CA+M3ks6Co2LxQ=EPODvwYrxmoRqiiQBr3Li4L3Nx3RY2As58dg-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2017-12-08 9:29 ` Daniel Lezcano
[not found] ` <56ba2617-ab7b-9715-928e-c922c1b32866-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org>
2017-12-08 9:31 ` Benjamin Gaignard
2017-11-14 8:52 ` [PATCH v8 5/6] clocksource: stm32: add clocksource support Benjamin Gaignard
2017-11-14 8:52 ` [PATCH v8 6/6] arm: dts: stm32: remove useless clocksource nodes Benjamin Gaignard
2017-11-27 10:44 ` [PATCH v8 0/6] stm32 clocksource driver rework Benjamin Gaignard
2017-12-05 10:12 ` Alexandre Torgue
2017-12-05 10:15 ` Daniel Lezcano
2017-12-05 10:16 ` Alexandre Torgue
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