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From: Baruch Siach <baruch@tkos.co.il>
To: "Thierry Reding" <thierry.reding@gmail.com>,
	"Uwe Kleine-König" <u.kleine-koenig@pengutronix.de>,
	"Lee Jones" <lee.jones@linaro.org>,
	"Linus Walleij" <linus.walleij@linaro.org>,
	"Bartosz Golaszewski" <bgolaszewski@baylibre.com>
Cc: Baruch Siach <baruch@tkos.co.il>, Andrew Lunn <andrew@lunn.ch>,
	Gregory Clement <gregory.clement@bootlin.com>,
	Russell King <linux@armlinux.org.uk>,
	Sebastian Hesselbarth <sebastian.hesselbarth@gmail.com>,
	Thomas Petazzoni <thomas.petazzoni@bootlin.com>,
	Chris Packham <chris.packham@alliedtelesis.co.nz>,
	Sascha Hauer <s.hauer@pengutronix.de>,
	Ralph Sennhauser <ralph.sennhauser@gmail.com>,
	linux-pwm@vger.kernel.org, linux-gpio@vger.kernel.org,
	linux-arm-kernel@lists.infradead.org
Subject: [PATCH 5/5] gpio: mvebu: document zero pwm duty cycle limitation
Date: Mon, 11 Jan 2021 13:17:06 +0200	[thread overview]
Message-ID: <fa809a148e2a008c124677d61ea4ecba55cea7d0.1610362661.git.baruch@tkos.co.il> (raw)
In-Reply-To: <cover.1610362661.git.baruch@tkos.co.il>

Add a comment on why the code never sets the 'on' register to zero.

Reported-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Baruch Siach <baruch@tkos.co.il>
---
 drivers/gpio/gpio-mvebu.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/gpio/gpio-mvebu.c b/drivers/gpio/gpio-mvebu.c
index eb7456fa6d86..4261e3b22b4e 100644
--- a/drivers/gpio/gpio-mvebu.c
+++ b/drivers/gpio/gpio-mvebu.c
@@ -706,6 +706,7 @@ static int mvebu_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm,
 	val = DIV_ROUND_UP_ULL(val, NSEC_PER_SEC);
 	if (val > UINT_MAX)
 		return -EINVAL;
+	/* zero 'on' value does not work as expected for some reason */
 	if (val)
 		on = val;
 	else
-- 
2.29.2


  parent reply	other threads:[~2021-01-11 11:19 UTC|newest]

Thread overview: 14+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-01-11 11:17 [PATCH 0/5] gpio: mvebu: pwm fixes and improvements Baruch Siach
2021-01-11 11:17 ` [PATCH 1/5] gpio: mvebu: fix pwm get_state period calculation Baruch Siach
2021-01-11 20:17   ` Uwe Kleine-König
2021-01-13  6:36     ` Baruch Siach
2021-01-13  8:17       ` Uwe Kleine-König
2021-01-11 11:17 ` [PATCH 2/5] gpio: mvebu: improve pwm period calculation accuracy Baruch Siach
2021-01-11 20:18   ` Uwe Kleine-König
2021-01-11 11:17 ` [PATCH 3/5] gpio: mvebu: make pwm apply/get_state closer to idempotent Baruch Siach
2021-01-11 20:20   ` Uwe Kleine-König
2021-01-11 11:17 ` [PATCH 4/5] gpio: mvebu: don't limit pwm period/duty_cycle to UINT_MAX Baruch Siach
2021-01-11 20:21   ` Uwe Kleine-König
2021-01-11 11:17 ` Baruch Siach [this message]
2021-01-11 20:24   ` [PATCH 5/5] gpio: mvebu: document zero pwm duty cycle limitation Uwe Kleine-König
2021-01-11 22:43     ` Russell King - ARM Linux admin

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