linux-kernel - [PATCH 4.5 079/124] gpio: pxa: fix legacy non pinctrl aware builds

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Date:	Mon, 18 Apr 2016 11:29:11 +0900
From:	Greg Kroah-Hartman <gregkh@...uxfoundation.org>
To:	linux-kernel@...r.kernel.org
Cc:	Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
	stable@...r.kernel.org, Guenter Roeck <guenter@...ck-us.net>,
	Robert Jarzmik <robert.jarzmik@...e.fr>,
	Linus Walleij <linus.walleij@...aro.org>
Subject: [PATCH 4.5 079/124] gpio: pxa: fix legacy non pinctrl aware builds

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

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

From: Robert Jarzmik <robert.jarzmik@...e.fr>

commit c4e5ffb6f224c1a4a9eaad82b19645ec22d1b24f upstream.

In legacy pxa builds, ie. non device-tree and platform-data only builds,
pinctrl is not yet available. As a consequence, the pinctrl gpio
direction change function is a stub, returning always success.

In the current state, the gpio driver direction function believes the
pinctrl direction change was successful, and exits without actually
changing the gpio direction.

This patch changes the logic :
 - if the pinctrl direction function fails, gpio direction will report
   that failure
 - if the pinctrl direction function succeeds, gpio direction is changed
   by the gpio driver anyway.
   This is sub optimal in the pinctrl aware case, as the gpio direction
   will be changed twice: once by pinctrl function and another time by
   the gpio direction function.

Yet it should be acceptable in this form, as this is functional for all
pxa platforms (device-tree and platform-data), and moreover changing a
gpio direction is very very seldom, usually in machine initialization,
seldom in drivers probe, and an exception for ac97 reset bug.

Fixes: a770d946371e ("gpio: pxa: add pin control gpio direction and request")
Reported-by: Guenter Roeck <guenter@...ck-us.net>
Tested-by: Guenter Roeck <guenter@...ck-us.net>
Signed-off-by: Robert Jarzmik <robert.jarzmik@...e.fr>
Signed-off-by: Linus Walleij <linus.walleij@...aro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@...uxfoundation.org>

---
 drivers/gpio/gpio-pxa.c |    4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

--- a/drivers/gpio/gpio-pxa.c
+++ b/drivers/gpio/gpio-pxa.c
@@ -283,8 +283,8 @@ static int pxa_gpio_direction_output(str
 	writel_relaxed(mask, base + (value ? GPSR_OFFSET : GPCR_OFFSET));
 
 	ret = pinctrl_gpio_direction_output(chip->base + offset);
-	if (!ret)
-		return 0;
+	if (ret)
+		return ret;
 
 	spin_lock_irqsave(&gpio_lock, flags);