gpio: max732x: add error handling for i2c_new_dummy

Message ID 1528774132-38287-1-git-send-email-jiazhouyang09@gmail.com
State New
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Series
  • gpio: max732x: add error handling for i2c_new_dummy
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Commit Message

Zhouyang Jia June 12, 2018, 3:28 a.m.
When i2c_new_dummy fails, the lack of error-handling code may
cause unexpected results.

This patch adds error-handling code after calling i2c_new_dummy.

Signed-off-by: Zhouyang Jia <jiazhouyang09@gmail.com>
---
 drivers/gpio/gpio-max732x.c | 12 ++++++++++++
 1 file changed, 12 insertions(+)

Comments

Andy Shevchenko June 12, 2018, 8:32 a.m. | #1
On Tue, Jun 12, 2018 at 6:28 AM, Zhouyang Jia <jiazhouyang09@gmail.com> wrote:
> When i2c_new_dummy fails, the lack of error-handling code may
> cause unexpected results.

What results?
Where is the analisys?

Would driver work w/o these dummy devices?
Linus Walleij June 14, 2018, 2:27 p.m. | #2
On Tue, Jun 12, 2018 at 5:28 AM, Zhouyang Jia <jiazhouyang09@gmail.com> wrote:

> When i2c_new_dummy fails, the lack of error-handling code may
> cause unexpected results.
>
> This patch adds error-handling code after calling i2c_new_dummy.
>
> Signed-off-by: Zhouyang Jia <jiazhouyang09@gmail.com>

Patch applied for non-critical fixes.

Yours,
Linus Walleij
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Andy Shevchenko June 15, 2018, 9:01 a.m. | #3
On Thu, Jun 14, 2018 at 5:27 PM, Linus Walleij <linus.walleij@linaro.org> wrote:
> On Tue, Jun 12, 2018 at 5:28 AM, Zhouyang Jia <jiazhouyang09@gmail.com> wrote:
>
>> When i2c_new_dummy fails, the lack of error-handling code may
>> cause unexpected results.
>>
>> This patch adds error-handling code after calling i2c_new_dummy.
>>
>> Signed-off-by: Zhouyang Jia <jiazhouyang09@gmail.com>
>
> Patch applied for non-critical fixes.

It might potentially be a regression if the driver used to work when
dummy device creation failed.

>
> Yours,
> Linus Walleij

Patch

diff --git a/drivers/gpio/gpio-max732x.c b/drivers/gpio/gpio-max732x.c
index 9d8bcc6..f03cb0b 100644
--- a/drivers/gpio/gpio-max732x.c
+++ b/drivers/gpio/gpio-max732x.c
@@ -653,6 +653,12 @@  static int max732x_probe(struct i2c_client *client,
 		chip->client_group_a = client;
 		if (nr_port > 8) {
 			c = i2c_new_dummy(client->adapter, addr_b);
+			if (!c) {
+				dev_err(&client->dev,
+					"Failed to allocate I2C device\n");
+				ret = -ENODEV;
+				goto out_failed;
+			}
 			chip->client_group_b = chip->client_dummy = c;
 		}
 		break;
@@ -660,6 +666,12 @@  static int max732x_probe(struct i2c_client *client,
 		chip->client_group_b = client;
 		if (nr_port > 8) {
 			c = i2c_new_dummy(client->adapter, addr_a);
+			if (!c) {
+				dev_err(&client->dev,
+					"Failed to allocate I2C device\n");
+				ret = -ENODEV;
+				goto out_failed;
+			}
 			chip->client_group_a = chip->client_dummy = c;
 		}
 		break;