[PATCH v4 03/15] staging: gpib: agilent_82357a: Handle gpib_register_driver() errors

Nihar Chaithanya posted 15 patches 1 year, 1 month ago
There is a newer version of this series
[PATCH v4 03/15] staging: gpib: agilent_82357a: Handle gpib_register_driver() errors
Posted by Nihar Chaithanya 1 year, 1 month ago
The usb_register() function can fail and returns an error value which
is not returned. The function gpib_register_driver() can also fail
which can result in semi-registered module.

In case gpib_register_driver() fails unregister the previous usb driver
registering function. Return the error value if gpib_register_driver()
or usb_register() functions fail.

Signed-off-by: Nihar Chaithanya <niharchaithanya@gmail.com>
---
 .../staging/gpib/agilent_82357a/agilent_82357a.c    | 13 ++++++++++---
 1 file changed, 10 insertions(+), 3 deletions(-)

diff --git a/drivers/staging/gpib/agilent_82357a/agilent_82357a.c b/drivers/staging/gpib/agilent_82357a/agilent_82357a.c
index bf05fb4a736b..60311ce8d164 100644
--- a/drivers/staging/gpib/agilent_82357a/agilent_82357a.c
+++ b/drivers/staging/gpib/agilent_82357a/agilent_82357a.c
@@ -1691,14 +1691,21 @@ static struct usb_driver agilent_82357a_bus_driver = {
 static int __init agilent_82357a_init_module(void)
 {
 	int i;
+	int ret = 0;
 
 	pr_info("agilent_82357a_gpib driver loading");
 	for (i = 0; i < MAX_NUM_82357A_INTERFACES; ++i)
 		agilent_82357a_driver_interfaces[i] = NULL;
-	usb_register(&agilent_82357a_bus_driver);
-	gpib_register_driver(&agilent_82357a_gpib_interface, THIS_MODULE);
 
-	return 0;
+	ret = usb_register(&agilent_82357a_bus_driver);
+	if (ret)
+		return ret;
+
+	ret = gpib_register_driver(&agilent_82357a_gpib_interface, THIS_MODULE);
+	if (ret)
+		usb_deregister(&agilent_82357a_bus_driver);
+
+	return ret;
 }
 
 static void __exit agilent_82357a_exit_module(void)
-- 
2.34.1
Re: [PATCH v4 03/15] staging: gpib: agilent_82357a: Handle gpib_register_driver() errors
Posted by Shuah Khan 1 year, 1 month ago
On 12/26/24 12:36, Nihar Chaithanya wrote:
> The usb_register() function can fail and returns an error value which
> is not returned. The function gpib_register_driver() can also fail
> which can result in semi-registered module.
> 
> In case gpib_register_driver() fails unregister the previous usb driver
> registering function. Return the error value if gpib_register_driver()
> or usb_register() functions fail.
> 
> Signed-off-by: Nihar Chaithanya <niharchaithanya@gmail.com>
> ---
>   .../staging/gpib/agilent_82357a/agilent_82357a.c    | 13 ++++++++++---
>   1 file changed, 10 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/staging/gpib/agilent_82357a/agilent_82357a.c b/drivers/staging/gpib/agilent_82357a/agilent_82357a.c
> index bf05fb4a736b..60311ce8d164 100644
> --- a/drivers/staging/gpib/agilent_82357a/agilent_82357a.c
> +++ b/drivers/staging/gpib/agilent_82357a/agilent_82357a.c
> @@ -1691,14 +1691,21 @@ static struct usb_driver agilent_82357a_bus_driver = {
>   static int __init agilent_82357a_init_module(void)
>   {
>   	int i;
> +	int ret = 0;
>   
>   	pr_info("agilent_82357a_gpib driver loading");

This message could be moved to the end of the routine saying
module init is complete - also fdor all of these messages,
dev_* might work better.

>   	for (i = 0; i < MAX_NUM_82357A_INTERFACES; ++i)
>   		agilent_82357a_driver_interfaces[i] = NULL;
> -	usb_register(&agilent_82357a_bus_driver);
> -	gpib_register_driver(&agilent_82357a_gpib_interface, THIS_MODULE);
>   
> -	return 0;
> +	ret = usb_register(&agilent_82357a_bus_driver);
> +	if (ret)
> +		return ret;
> +
> +	ret = gpib_register_driver(&agilent_82357a_gpib_interface, THIS_MODULE);
> +	if (ret)
> +		usb_deregister(&agilent_82357a_bus_driver);
> +
> +	return ret;
>   }
>   
>   static void __exit agilent_82357a_exit_module(void)

thanks,
-- Shuah