From: Phil Reid <preid@electromag.com.au>
Date: Tue, 8 Nov 2016 06:00:45 +0000 (+0800)
Subject: gpio: pca953x: Fix corruption of other gpios in set_multiple.
X-Git-Tag: v4.8.11~1
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=a9a0027757f8c317f1d7334c095bde96b4a0f84c;p=thirdparty%2Fkernel%2Fstable.git

gpio: pca953x: Fix corruption of other gpios in set_multiple.

commit 53f8d322234649b4d6f1515b20c127a577efd164 upstream.

gpiod_set_array_value_complex does not clear the bits field.
Therefore when the drivers set_multiple funciton is called bits outside
the mask are undefined and can be either set or not. So bank_val needs
to be masked with bank_mask before or with the reg_val cache.

Fixes: b4818afeacbd ("gpio: pca953x: Add set_multiple to allow multiple")
Signed-off-by: Phil Reid <preid@electromag.com.au>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---

diff --git a/drivers/gpio/gpio-pca953x.c b/drivers/gpio/gpio-pca953x.c
index 5fae629c241e6..47d08b9da60d1 100644
--- a/drivers/gpio/gpio-pca953x.c
+++ b/drivers/gpio/gpio-pca953x.c
@@ -380,6 +380,7 @@ static void pca953x_gpio_set_multiple(struct gpio_chip *gc,
 		if(bankmask) {
 			unsigned bankval  = bits[bank / sizeof(*bits)] >>
 					    ((bank % sizeof(*bits)) * 8);
+			bankval &= bankmask;
 			reg_val[bank] = (reg_val[bank] & ~bankmask) | bankval;
 		}
 	}