linux-kernel - [PATCH AUTOSEL 5.6 15/73] pwm: imx27: Fix clock handling in pwm_imx27

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Message-Id: <20200418134815.6519-15-sashal@kernel.org>
Date:   Sat, 18 Apr 2020 09:47:17 -0400
From:   Sasha Levin <sashal@...nel.org>
To:     linux-kernel@...r.kernel.org, stable@...r.kernel.org
Cc:     Uwe Kleine-König 
        <u.kleine-koenig@...gutronix.de>,
        Thierry Reding <thierry.reding@...il.com>,
        Sasha Levin <sashal@...nel.org>, linux-pwm@...r.kernel.org,
        linux-arm-kernel@...ts.infradead.org
Subject: [PATCH AUTOSEL 5.6 15/73] pwm: imx27: Fix clock handling in pwm_imx27_apply()

From: Uwe Kleine-König <u.kleine-koenig@...gutronix.de>

[ Upstream commit 15d4dbd601591858611184f9ddeb5bf21569159c ]

pwm_imx27_apply() enables the clocks if the previous PWM state was
disabled. Given that the clocks are supposed to be left on iff the PWM
is running, the decision to disable the clocks at the end of the
function must not depend on the previous state.

Without this fix the enable count of the two affected clocks increases
by one whenever ->apply() changes from one disabled state to another.

Fixes: bd88d319abe9 ("pwm: imx27: Unconditionally write state to hardware")
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@...gutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@...il.com>
Signed-off-by: Sasha Levin <sashal@...nel.org>
---
 drivers/pwm/pwm-imx27.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/pwm/pwm-imx27.c b/drivers/pwm/pwm-imx27.c
index 35a7ac42269c2..7e5ed01529773 100644
--- a/drivers/pwm/pwm-imx27.c
+++ b/drivers/pwm/pwm-imx27.c
@@ -289,7 +289,7 @@ static int pwm_imx27_apply(struct pwm_chip *chip, struct pwm_device *pwm,
 
 	writel(cr, imx->mmio_base + MX3_PWMCR);
 
-	if (!state->enabled && cstate.enabled)
+	if (!state->enabled)
 		pwm_imx27_clk_disable_unprepare(chip);
 
 	return 0;
-- 
2.20.1