linux-kernel - [PATCH 6/6] nvmem: increase the reference count of a gpio passed over config

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Message-Id: <20200217195435.9309-7-brgl@bgdev.pl>
Date:   Mon, 17 Feb 2020 20:54:35 +0100
From:   Bartosz Golaszewski <brgl@...ev.pl>
To:     Linus Walleij <linus.walleij@...aro.org>,
        Srinivas Kandagatla <srinivas.kandagatla@...aro.org>,
        Khouloud Touil <ktouil@...libre.com>
Cc:     linux-gpio@...r.kernel.org, linux-kernel@...r.kernel.org,
        Bartosz Golaszewski <bgolaszewski@...libre.com>
Subject: [PATCH 6/6] nvmem: increase the reference count of a gpio passed over config

From: Bartosz Golaszewski <bgolaszewski@...libre.com>

We can obtain the write-protect GPIO in nvmem_register() by requesting
it ourselves or by storing the gpio_desc passed in nvmem_config. In the
latter case we need to increase the reference count so that it gets
freed correctly.

Signed-off-by: Bartosz Golaszewski <bgolaszewski@...libre.com>
---
 drivers/nvmem/core.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/drivers/nvmem/core.c b/drivers/nvmem/core.c
index 096c7bae9e74..b7b1e3194453 100644
--- a/drivers/nvmem/core.c
+++ b/drivers/nvmem/core.c
@@ -349,11 +349,13 @@ struct nvmem_device *nvmem_register(const struct nvmem_config *config)
 		return ERR_PTR(rval);
 	}
 
-	if (config->wp_gpio)
+	if (config->wp_gpio) {
 		nvmem->wp_gpio = config->wp_gpio;
-	else
+		gpiod_ref(config->wp_gpio);
+	} else {
 		nvmem->wp_gpio = gpiod_get_optional(config->dev, "wp",
 						    GPIOD_OUT_HIGH);
+	}
 	if (IS_ERR(nvmem->wp_gpio))
 		goto err_ida_remove;
 
-- 
2.25.0