linux-kernel - [PATCH 5.10 13/93] gpio: pca953x: do not ignore i2c errors

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Date:   Mon,  4 Oct 2021 14:52:11 +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,
        Andrey Gusakov <andrey.gusakov@...entembedded.com>,
        Nikita Yushchenko <nikita.yoush@...entembedded.com>,
        Bartosz Golaszewski <brgl@...ev.pl>
Subject: [PATCH 5.10 13/93] gpio: pca953x: do not ignore i2c errors

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

commit 540cffbab8b8e6c52a4121666ca18d6e94586ed2 upstream.

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.

Cc: stable@...r.kernel.org
Signed-off-by: Andrey Gusakov <andrey.gusakov@...entembedded.com>
Signed-off-by: Nikita Yushchenko <nikita.yoush@...entembedded.com>
Signed-off-by: Bartosz Golaszewski <brgl@...ev.pl>
Signed-off-by: Greg Kroah-Hartman <gregkh@...uxfoundation.org>
---
 drivers/gpio/gpio-pca953x.c |   11 ++---------
 1 file changed, 2 insertions(+), 9 deletions(-)

--- a/drivers/gpio/gpio-pca953x.c
+++ b/drivers/gpio/gpio-pca953x.c
@@ -467,15 +467,8 @@ static int pca953x_gpio_get_value(struct
 	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);
 }