linux-kernel - [tip: timers/core] clocksource/drivers/timer-ti-dm: Do not update counter on updating the period

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Message-ID: <158460767223.28353.3956921614051586529.tip-bot2@tip-bot2>
Date:   Thu, 19 Mar 2020 08:47:52 -0000
From:   "tip-bot2 for Lokesh Vutla" <tip-bot2@...utronix.de>
To:     linux-tip-commits@...r.kernel.org
Cc:     Lokesh Vutla <lokeshvutla@...com>,
        Tony Lindgren <tony@...mide.com>,
        Daniel Lezcano <daniel.lezcano@...aro.org>,
        x86 <x86@...nel.org>, LKML <linux-kernel@...r.kernel.org>
Subject: [tip: timers/core] clocksource/drivers/timer-ti-dm: Do not update
 counter on updating the period

The following commit has been merged into the timers/core branch of tip:

Commit-ID:     6ce4fcb015a1a1290ffafcf3554901b40f9322df
Gitweb:        https://git.kernel.org/tip/6ce4fcb015a1a1290ffafcf3554901b40f9322df
Author:        Lokesh Vutla <lokeshvutla@...com>
AuthorDate:    Mon, 24 Feb 2020 10:37:53 +05:30
Committer:     Daniel Lezcano <daniel.lezcano@...aro.org>
CommitterDate: Thu, 27 Feb 2020 10:26:23 +01:00

clocksource/drivers/timer-ti-dm: Do not update counter on updating the period

Write to trigger register(OMAP_TIMER_TRIGGER_REG) will load the value
in Load register(OMAP_TIMER_LOAD_REG) into Counter register
(OMAP_TIMER_COUNTER_REG).

omap_dm_timer_set_load() writes into trigger register every time load
register is updated. When timer is configured in pwm mode, this causes
disruption in current pwm cycle, which is not expected especially when
pwm is used as PPS signal for synchronized PTP clocks. So do not write
into trigger register on updating the period.

Signed-off-by: Lokesh Vutla <lokeshvutla@...com>
Tested-by: Tony Lindgren <tony@...mide.com>
Signed-off-by: Daniel Lezcano <daniel.lezcano@...aro.org>
Link: https://lore.kernel.org/r/20200224050753.17784-3-lokeshvutla@ti.com
---
 drivers/clocksource/timer-ti-dm.c | 1 -
 1 file changed, 1 deletion(-)

diff --git a/drivers/clocksource/timer-ti-dm.c b/drivers/clocksource/timer-ti-dm.c
index 269a994..acc9360 100644
--- a/drivers/clocksource/timer-ti-dm.c
+++ b/drivers/clocksource/timer-ti-dm.c
@@ -577,7 +577,6 @@ static int omap_dm_timer_set_load(struct omap_dm_timer *timer, int autoreload,
 	omap_dm_timer_write_reg(timer, OMAP_TIMER_CTRL_REG, l);
 	omap_dm_timer_write_reg(timer, OMAP_TIMER_LOAD_REG, load);
 
-	omap_dm_timer_write_reg(timer, OMAP_TIMER_TRIGGER_REG, 0);
 	/* Save the context */
 	timer->context.tclr = l;
 	timer->context.tldr = load;