From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753784AbdKNIx5 (ORCPT ); Tue, 14 Nov 2017 03:53:57 -0500 Received: from mail-wm0-f67.google.com ([74.125.82.67]:51650 "EHLO mail-wm0-f67.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753280AbdKNIx0 (ORCPT ); Tue, 14 Nov 2017 03:53:26 -0500 X-Google-Smtp-Source: AGs4zMby1IDgT/weWvW+jg1BVBzdai0GEWTNezJADSs43Kcb8e9445qRVHgW+vy4y+NW+b/XK7C66Q== From: Benjamin Gaignard To: robh+dt@kernel.org, mark.rutland@arm.com, linux@armlinux.org.uk, mcoquelin.stm32@gmail.com, alexandre.torgue@st.com, daniel.lezcano@linaro.org, tglx@linutronix.de, ludovic.barre@st.com, julien.thierry@arm.com, sudeep.holla@arm.com, arnd@arndb.de Cc: devicetree@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, 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> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1510649563-22975-1-git-send-email-benjamin.gaignard@linaro.org> References: <1510649563-22975-1-git-send-email-benjamin.gaignard@linaro.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@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