[PATCH] NFC: st21nfcb: fix error handling of irq_of_parse_and_map

[PATCH] NFC: st21nfcb: fix error handling of irq_of_parse_and_map

[Dmitry Torokhov]

Return value of irq_of_parse_and_map() is unsigned int, with 0
indicating failure, so testing for negative result never works.

Also report error returned by devm_gpio_request_one instead of
clobbering it with -ENODEV.

Signed-off-by: Dmitry Torokhov <dtor@chromium.org>
---

Not tested, found by casual code inspection.

 drivers/nfc/st21nfcb/i2c.c | 11 +++++------
 1 file changed, 5 insertions(+), 6 deletions(-)

diff --git a/drivers/nfc/st21nfcb/i2c.c b/drivers/nfc/st21nfcb/i2c.c
index c5d2427..abe73ec 100644
--- a/drivers/nfc/st21nfcb/i2c.c
+++ b/drivers/nfc/st21nfcb/i2c.c
@@ -258,19 +258,18 @@ static int st21nfcb_nci_i2c_of_request_resources(struct i2c_client *client)
 				GPIOF_OUT_INIT_HIGH, "clf_reset");
 	if (r) {
 		nfc_err(&client->dev, "Failed to request reset pin\n");
-		return -ENODEV;
+		return r;
 	}
 	phy->gpio_reset = gpio;
 
 	/* IRQ */
-	r = irq_of_parse_and_map(pp, 0);
-	if (r < 0) {
-		nfc_err(&client->dev, "Unable to get irq, error: %d\n", r);
-		return r;
+	client->irq = irq_of_parse_and_map(pp, 0);
+	if (!client->irq) {
+		nfc_err(&client->dev, "Unable to get irq\n");
+		return -EINVAL;
 	}
 
 	phy->irq_polarity = irq_get_trigger_type(r);
-	client->irq = r;
 
 	return 0;
 }
-- 
2.1.0.rc2.206.gedb03e5


-- 
Dmitry

Re: [PATCH] NFC: st21nfcb: fix error handling of irq_of_parse_and_map

[Christophe RICARD]

Hi Dmitry,

Thank you for your feedback.
A patch got already pushed earlier this month:
https://lists.01.org/pipermail/linux-nfc/2014-November/003126.html

The i2c-core is already running the i2c_of_parse_and_map function when
registering the slave device when using dts. This step got removed for
this reason. 

However, i will take into account your second point in order to report
devm_gpio_request_one instead of -ENODEV in a future patchset.

Best Regards
Christophe

On Fri, 14 Nov 2014 14:35:27 -0800
Dmitry Torokhov <dtor@chromium.org> wrote:

> Return value of irq_of_parse_and_map() is unsigned int, with 0
> indicating failure, so testing for negative result never works.
> 
> Also report error returned by devm_gpio_request_one instead of
> clobbering it with -ENODEV.
> 
> Signed-off-by: Dmitry Torokhov <dtor@chromium.org>
> ---
> 
> Not tested, found by casual code inspection.
> 
>  drivers/nfc/st21nfcb/i2c.c | 11 +++++------
>  1 file changed, 5 insertions(+), 6 deletions(-)
> 
> diff --git a/drivers/nfc/st21nfcb/i2c.c b/drivers/nfc/st21nfcb/i2c.c
> index c5d2427..abe73ec 100644
> --- a/drivers/nfc/st21nfcb/i2c.c
> +++ b/drivers/nfc/st21nfcb/i2c.c
> @@ -258,19 +258,18 @@ static int
> st21nfcb_nci_i2c_of_request_resources(struct i2c_client *client)
> GPIOF_OUT_INIT_HIGH, "clf_reset"); if (r) {
>  		nfc_err(&client->dev, "Failed to request reset
> pin\n");
> -		return -ENODEV;
> +		return r;
>  	}
>  	phy->gpio_reset = gpio;
>  
>  	/* IRQ */
> -	r = irq_of_parse_and_map(pp, 0);
> -	if (r < 0) {
> -		nfc_err(&client->dev, "Unable to get irq, error:
> %d\n", r);
> -		return r;
> +	client->irq = irq_of_parse_and_map(pp, 0);
> +	if (!client->irq) {
> +		nfc_err(&client->dev, "Unable to get irq\n");
> +		return -EINVAL;
>  	}
>  
>  	phy->irq_polarity = irq_get_trigger_type(r);
> -	client->irq = r;
>  
>  	return 0;
>  }