linux-kernel - [PATCH] gpio: pca953x: do not ignore i2c errors

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Date:   Thu, 23 Sep 2021 20:22:16 +0300
From:   Nikita Yushchenko <nikita.yoush@...entembedded.com>
To:     Linus Walleij <linus.walleij@...aro.org>,
        Bartosz Golaszewski <bgolaszewski@...libre.com>
Cc:     linux-gpio@...r.kernel.org, linux-kernel@...r.kernel.org,
        Andrey Gusakov <andrey.gusakov@...entembedded.com>,
        Nikita Yushchenko <nikita.yoush@...entembedded.com>
Subject: [PATCH] gpio: pca953x: do not ignore i2c errors

From: Andrey Gusakov <andrey.gusakov@...entembedded.com>

Per gpio_chip interface, error shall be proparated to the caller.

Attempt to silent diagnostics by returning zero (as written in the
comment) is plain wrong, because the zero return can be interpreted by
the caller as the gpio value.

Signed-off-by: Andrey Gusakov <andrey.gusakov@...entembedded.com>
Signed-off-by: Nikita Yushchenko <nikita.yoush@...entembedded.com>
---
 drivers/gpio/gpio-pca953x.c | 11 ++---------
 1 file changed, 2 insertions(+), 9 deletions(-)

diff --git a/drivers/gpio/gpio-pca953x.c b/drivers/gpio/gpio-pca953x.c
index f5cfc0698799..8ebf369b3ba0 100644
--- a/drivers/gpio/gpio-pca953x.c
+++ b/drivers/gpio/gpio-pca953x.c
@@ -468,15 +468,8 @@ static int pca953x_gpio_get_value(struct gpio_chip *gc, unsigned off)
 	mutex_lock(&chip->i2c_lock);
 	ret = regmap_read(chip->regmap, inreg, &reg_val);
 	mutex_unlock(&chip->i2c_lock);
-	if (ret < 0) {
-		/*
-		 * NOTE:
-		 * diagnostic already emitted; that's all we should
-		 * do unless gpio_*_value_cansleep() calls become different
-		 * from their nonsleeping siblings (and report faults).
-		 */
-		return 0;
-	}
+	if (ret < 0)
+		return ret;
 
 	return !!(reg_val & bit);
 }
-- 
2.30.2