linux-kernel - [PATCH AUTOSEL 4.9 138/251] pwm: meson: Don't disable PWM when setting duty repeatedly

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Message-Id: <20200116173641.22137-98-sashal@kernel.org>
Date:   Thu, 16 Jan 2020 12:34:47 -0500
From:   Sasha Levin <sashal@...nel.org>
To:     linux-kernel@...r.kernel.org, stable@...r.kernel.org
Cc:     Bichao Zheng <bichao.zheng@...ogic.com>,
        Martin Blumenstingl <martin.blumenstingl@...glemail.com>,
        Neil Armstrong <narmstrong@...libre.com>,
        Thierry Reding <thierry.reding@...il.com>,
        Sasha Levin <sashal@...nel.org>, linux-pwm@...r.kernel.org,
        linux-arm-kernel@...ts.infradead.org,
        linux-amlogic@...ts.infradead.org
Subject: [PATCH AUTOSEL 4.9 138/251] pwm: meson: Don't disable PWM when setting duty repeatedly

From: Bichao Zheng <bichao.zheng@...ogic.com>

[ Upstream commit a279345807e1e0ae79567a52cfdd9d30c9174a3c ]

There is an abnormally low about 20ms,when setting duty repeatedly.
Because setting the duty will disable PWM and then enable. Delete
this operation now.

Fixes: 211ed630753d2f ("pwm: Add support for Meson PWM Controller")
Signed-off-by: Bichao Zheng <bichao.zheng@...ogic.com>
[ Dropped code instead of hiding it behind a comment ]
Signed-off-by: Martin Blumenstingl <martin.blumenstingl@...glemail.com>
Reviewed-by: Neil Armstrong <narmstrong@...libre.com>
Signed-off-by: Thierry Reding <thierry.reding@...il.com>
Signed-off-by: Sasha Levin <sashal@...nel.org>
---
 drivers/pwm/pwm-meson.c | 5 -----
 1 file changed, 5 deletions(-)

diff --git a/drivers/pwm/pwm-meson.c b/drivers/pwm/pwm-meson.c
index f58a4867b519..a196439ee14c 100644
--- a/drivers/pwm/pwm-meson.c
+++ b/drivers/pwm/pwm-meson.c
@@ -320,11 +320,6 @@ static int meson_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm,
 	if (state->period != channel->state.period ||
 	    state->duty_cycle != channel->state.duty_cycle ||
 	    state->polarity != channel->state.polarity) {
-		if (channel->state.enabled) {
-			meson_pwm_disable(meson, pwm->hwpwm);
-			channel->state.enabled = false;
-		}
-
 		if (state->polarity != channel->state.polarity) {
 			if (state->polarity == PWM_POLARITY_NORMAL)
 				meson->inverter_mask |= BIT(pwm->hwpwm);
-- 
2.20.1