All of lore.kernel.org
 help / color / mirror / Atom feed
From: Lokesh Vutla <lokeshvutla@ti.com>
To: Tony Lindgren <tony@atomide.com>,
	Daniel Lezcano <daniel.lezcano@linaro.org>,
	Thomas Gleixner <tglx@linutronix.de>
Cc: "Linux OMAP Mailing List" <linux-omap@vger.kernel.org>,
	linux-kernel@vger.kernel.org,
	"Thierry Reding" <thierry.reding@gmail.com>,
	"Uwe Kleine-König" <u.kleine-koenig@pengutronix.de>,
	linux-pwm@vger.kernel.org, "Sekhar Nori" <nsekhar@ti.com>,
	"Tero Kristo" <t-kristo@ti.com>,
	"Lokesh Vutla" <lokeshvutla@ti.com>,
	"Tony Lindgren" <tony@atomide.com>
Subject: [PATCH v3 4/6] clocksource: timer-ti-dm: Do not update counter on updating the period
Date: Thu, 5 Mar 2020 13:57:13 +0530	[thread overview]
Message-ID: <20200305082715.15861-5-lokeshvutla@ti.com> (raw)
In-Reply-To: <20200305082715.15861-1-lokeshvutla@ti.com>

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.

Tested-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Lokesh Vutla <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 e6b6123ec567..8f6d477d2078 100644
--- a/drivers/clocksource/timer-ti-dm.c
+++ b/drivers/clocksource/timer-ti-dm.c
@@ -548,7 +548,6 @@ 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);
 	omap_dm_timer_disable(timer);
 	return 0;
 }
-- 
2.23.0


WARNING: multiple messages have this Message-ID (diff)
From: Lokesh Vutla <lokeshvutla@ti.com>
To: Daniel Lezcano <daniel.lezcano@linaro.org>,
	Thomas Gleixner <tglx@linutronix.de>
Cc: "Linux OMAP Mailing List" <linux-omap@vger.kernel.org>,
	linux-kernel@vger.kernel.org,
	"Thierry Reding" <thierry.reding@gmail.com>,
	"Uwe Kleine-König" <u.kleine-koenig@pengutronix.de>,
	linux-pwm@vger.kernel.org, "Sekhar Nori" <nsekhar@ti.com>,
	"Tero Kristo" <t-kristo@ti.com>,
	"Lokesh Vutla" <lokeshvutla@ti.com>,
	"Tony Lindgren" <tony@atomide.com>
Subject: [PATCH v3 4/6] clocksource: timer-ti-dm: Do not update counter on updating the period
Date: Thu, 5 Mar 2020 13:57:13 +0530	[thread overview]
Message-ID: <20200305082715.15861-5-lokeshvutla@ti.com> (raw)
In-Reply-To: <20200305082715.15861-1-lokeshvutla@ti.com>

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.

Tested-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Lokesh Vutla <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 e6b6123ec567..8f6d477d2078 100644
--- a/drivers/clocksource/timer-ti-dm.c
+++ b/drivers/clocksource/timer-ti-dm.c
@@ -548,7 +548,6 @@ 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);
 	omap_dm_timer_disable(timer);
 	return 0;
 }
-- 
2.23.0

  parent reply	other threads:[~2020-03-05  8:28 UTC|newest]

Thread overview: 27+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-03-05  8:27 [PATCH v3 0/6] clocksource: timer-ti-dm: Prepare for dynamic pwm period updates Lokesh Vutla
2020-03-05  8:27 ` [PATCH v3 1/6] clocksource: timer-ti-dm: Convert to SPDX identifier Lokesh Vutla
2020-03-06 16:57   ` Tony Lindgren
2020-03-19  8:47   ` [tip: timers/core] clocksource/drivers/timer-ti-dm: " tip-bot2 for Lokesh Vutla
2020-03-05  8:27 ` [PATCH v3 2/6] clocksource: timer-ti-dm: Prepare for using cpuidle Lokesh Vutla
2020-03-05  8:27   ` Lokesh Vutla
2020-03-19  8:47   ` [tip: timers/core] clocksource/drivers/timer-ti-dm: " tip-bot2 for Tony Lindgren
2020-03-05  8:27 ` [PATCH v3 3/6] clocksource: timer-ti-dm: Implement cpu_pm notifier for context save and restore Lokesh Vutla
2020-03-05  8:27   ` Lokesh Vutla
2020-03-16 10:51   ` Daniel Lezcano
2020-03-16 11:14   ` [PATCH v4 " Lokesh Vutla
2020-03-16 11:14     ` Lokesh Vutla
2020-03-19  8:47     ` [tip: timers/core] clocksource/drivers/timer-ti-dm: " tip-bot2 for Lokesh Vutla
2020-03-05  8:27 ` Lokesh Vutla [this message]
2020-03-05  8:27   ` [PATCH v3 4/6] clocksource: timer-ti-dm: Do not update counter on updating the period Lokesh Vutla
2020-03-19  8:47   ` [tip: timers/core] clocksource/drivers/timer-ti-dm: " tip-bot2 for Lokesh Vutla
2020-03-05  8:27 ` [PATCH v3 5/6] clocksource: timer-ti-dm: Add support to get pwm current status Lokesh Vutla
2020-03-06 17:08   ` Tony Lindgren
2020-03-19  8:47   ` [tip: timers/core] clocksource/drivers/timer-ti-dm: " tip-bot2 for Lokesh Vutla
2020-03-05  8:27 ` [PATCH v3 6/6] clocksource: timer-ti-dm: Enable autoreload in set_pwm Lokesh Vutla
2020-03-06 17:18   ` Tony Lindgren
2020-03-19  8:47   ` [tip: timers/core] clocksource/drivers/timer-ti-dm: " tip-bot2 for Lokesh Vutla
2020-03-30 13:18   ` [PATCH v3 6/6] clocksource: timer-ti-dm: " Thierry Reding
2020-03-06 17:19 ` [PATCH v3 0/6] clocksource: timer-ti-dm: Prepare for dynamic pwm period updates Tony Lindgren
2020-03-12 11:10   ` Daniel Lezcano
2020-03-12 17:26     ` Tony Lindgren
2020-03-16 12:41       ` Daniel Lezcano

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20200305082715.15861-5-lokeshvutla@ti.com \
    --to=lokeshvutla@ti.com \
    --cc=daniel.lezcano@linaro.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-omap@vger.kernel.org \
    --cc=linux-pwm@vger.kernel.org \
    --cc=nsekhar@ti.com \
    --cc=t-kristo@ti.com \
    --cc=tglx@linutronix.de \
    --cc=thierry.reding@gmail.com \
    --cc=tony@atomide.com \
    --cc=u.kleine-koenig@pengutronix.de \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body. 
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.