Patchwork [v3] i2c-mux-gpio: Check gpio_direction_output return value

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Submitter Jean Delvare
Date March 7, 2013, 8:35 a.m.
Message ID <20130307093553.4bc1595f@endymion.delvare>
Download mbox | patch
Permalink /patch/225767/
State Accepted
Headers show

Comments

Jean Delvare - March 7, 2013, 8:35 a.m.
gpio_direction_output() may fail, check for that and deal with it
appropriately. Also log an error message if gpio_request() fails.

Signed-off-by: Jean Delvare <khali@linux-fr.org>
Cc: Peter Korsgaard <peter.korsgaard@barco.com>
Cc: Wolfram Sang <wsa@the-dreams.de>
---
Changes since v2:
 * Refreshed so that it applies on top of the most recent version of
   the driver.

 drivers/i2c/muxes/i2c-mux-gpio.c |   17 ++++++++++++++---
 1 file changed, 14 insertions(+), 3 deletions(-)
Peter Korsgaard - March 7, 2013, 8:45 a.m.
>>>>> "JD" == Jean Delvare <khali@linux-fr.org> writes:

JD> gpio_direction_output() may fail, check for that and deal with it
JD> appropriately. Also log an error message if gpio_request() fails.

JD> Signed-off-by: Jean Delvare <khali@linux-fr.org>
JD> Cc: Peter Korsgaard <peter.korsgaard@barco.com>
JD> Cc: Wolfram Sang <wsa@the-dreams.de>

Acked-by: Peter Korsgaard <peter.korsgaard@barco.com>
Wolfram Sang - March 27, 2013, 8:22 a.m.
On Thu, Mar 07, 2013 at 09:35:53AM +0100, Jean Delvare wrote:
> gpio_direction_output() may fail, check for that and deal with it
> appropriately. Also log an error message if gpio_request() fails.
> 
> Signed-off-by: Jean Delvare <khali@linux-fr.org>

Applied to for-next, thanks!

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Patch

--- linux-3.8.orig/drivers/i2c/muxes/i2c-mux-gpio.c	2013-03-07 09:06:31.431159507 +0100
+++ linux-3.8/drivers/i2c/muxes/i2c-mux-gpio.c	2013-03-07 09:07:02.739878467 +0100
@@ -201,10 +201,21 @@  static int i2c_mux_gpio_probe(struct pla
 
 	for (i = 0; i < mux->data.n_gpios; i++) {
 		ret = gpio_request(gpio_base + mux->data.gpios[i], "i2c-mux-gpio");
-		if (ret)
+		if (ret) {
+			dev_err(&pdev->dev, "Failed to request GPIO %d\n",
+				mux->data.gpios[i]);
 			goto err_request_gpio;
-		gpio_direction_output(gpio_base + mux->data.gpios[i],
-				      initial_state & (1 << i));
+		}
+
+		ret = gpio_direction_output(gpio_base + mux->data.gpios[i],
+					    initial_state & (1 << i));
+		if (ret) {
+			dev_err(&pdev->dev,
+				"Failed to set direction of GPIO %d to output\n",
+				mux->data.gpios[i]);
+			i++;	/* gpio_request above succeeded, so must free */
+			goto err_request_gpio;
+		}
 	}
 
 	for (i = 0; i < mux->data.n_values; i++) {