linux-kernel - [PATCH 4.4 43/73] pwm: Mark all devices as "might sleep"

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Message-Id: <20160928090437.543855807@linuxfoundation.org>
Date:   Wed, 28 Sep 2016 11:05:13 +0200
From:   Greg Kroah-Hartman <gregkh@...uxfoundation.org>
To:     linux-kernel@...r.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        stable@...r.kernel.org, Thierry Reding <thierry.reding@...il.com>,
        Krzysztof Kozlowski <krzk@...nel.org>
Subject: [PATCH 4.4 43/73] pwm: Mark all devices as "might sleep"

4.4-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Thierry Reding <thierry.reding@...il.com>

commit ff01c944cfa939f3474c28d88223213494aedf0b upstream.

Commit d1cd21427747 ("pwm: Set enable state properly on failed call to
enable") introduced a mutex that is needed to protect internal state of
PWM devices. Since that mutex is acquired in pwm_set_polarity() and in
pwm_enable() and might potentially block, all PWM devices effectively
become "might sleep".

It's rather pointless to keep the .can_sleep field around, but given
that there are external users let's postpone the removal for the next
release cycle.

Signed-off-by: Thierry Reding <thierry.reding@...il.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@...uxfoundation.org>
Fixes: d1cd21427747 ("pwm: Set enable state properly on failed call to enable")
Signed-off-by: Krzysztof Kozlowski <krzk@...nel.org>

---
 drivers/pwm/core.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/drivers/pwm/core.c
+++ b/drivers/pwm/core.c
@@ -889,7 +889,7 @@ EXPORT_SYMBOL_GPL(devm_pwm_put);
   */
 bool pwm_can_sleep(struct pwm_device *pwm)
 {
-	return pwm->chip->can_sleep;
+	return true;
 }
 EXPORT_SYMBOL_GPL(pwm_can_sleep);