From: Phil Reid <preid@electromag.com.au>
Date: Tue, 8 Nov 2016 05:18:11 +0000 (+0800)
Subject: gpio: pca953x: Move memcpy into mutex lock for set multiple
X-Git-Tag: v4.8.11~2
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=88fce76cf59055ddf97667001dbd26577b8760e0;p=thirdparty%2Fkernel%2Fstable.git

gpio: pca953x: Move memcpy into mutex lock for set multiple

commit 386377b5473043c09b2de40bfe5abfb0fc87e1b4 upstream.

Need to ensure that reg_output is not updated while setting multiple
bits. This makes the mutex locking behaviour for the set_multiple call
consistent with that of the set_value call.

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 02f2a5621bb0f..5fae629c241e6 100644
--- a/drivers/gpio/gpio-pca953x.c
+++ b/drivers/gpio/gpio-pca953x.c
@@ -372,8 +372,8 @@ static void pca953x_gpio_set_multiple(struct gpio_chip *gc,
 		break;
 	}
 
-	memcpy(reg_val, chip->reg_output, NBANK(chip));
 	mutex_lock(&chip->i2c_lock);
+	memcpy(reg_val, chip->reg_output, NBANK(chip));
 	for(bank=0; bank<NBANK(chip); bank++) {
 		unsigned bankmask = mask[bank / sizeof(*mask)] >>
 				    ((bank % sizeof(*mask)) * 8);