linux-kernel - [PATCH v2 2/3] gpiolib: use a more explicit retval logic in gpiochip_get

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Message-Id: <20250226-retval-fixes-v2-2-c8dc57182441@linaro.org>
Date: Wed, 26 Feb 2025 11:12:30 +0100
From: Bartosz Golaszewski <brgl@...ev.pl>
To: Linus Walleij <linus.walleij@...aro.org>, 
 Bartosz Golaszewski <brgl@...ev.pl>, 
 Marek Szyprowski <m.szyprowski@...sung.com>, 
 Andy Shevchenko <andriy.shevchenko@...el.com>
Cc: linux-gpio@...r.kernel.org, linux-kernel@...r.kernel.org, 
 Bartosz Golaszewski <bartosz.golaszewski@...aro.org>, 
 Andy Shevchenko <andriy.shevchenko@...ux.intel.com>
Subject: [PATCH v2 2/3] gpiolib: use a more explicit retval logic in
 gpiochip_get_direction()

From: Bartosz Golaszewski <bartosz.golaszewski@...aro.org>

We have existing macros for direction settings so we don't need to rely
on the magic value of 1 in the retval check. Use readable logic that
explicitly says we expect INPUT, OUTPUT or a negative errno and nothing
else in gpiochip_get_direction().

Fixes: e623c4303ed1 ("gpiolib: sanitize the return value of gpio_chip::get_direction()")
Suggested-by: Andy Shevchenko <andriy.shevchenko@...el.com>
Closes: https://lore.kernel.org/all/Z7yfTggRrk3K6srs@black.fi.intel.com/
Reviewed-by: Andy Shevchenko <andriy.shevchenko@...ux.intel.com>
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@...aro.org>
---
 drivers/gpio/gpiolib.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c
index 0d325cc41af3..6f4efab237e6 100644
--- a/drivers/gpio/gpiolib.c
+++ b/drivers/gpio/gpiolib.c
@@ -352,7 +352,10 @@ static int gpiochip_get_direction(struct gpio_chip *gc, unsigned int offset)
 		return -EOPNOTSUPP;
 
 	ret = gc->get_direction(gc, offset);
-	if (ret > 1)
+	if (ret < 0)
+		return ret;
+
+	if (ret != GPIO_LINE_DIRECTION_OUT && ret != GPIO_LINE_DIRECTION_IN)
 		ret = -EBADE;
 
 	return ret;

-- 
2.45.2