[PATCH] usb: move assignment out of if condition

[PATCH] usb: move assignment out of if condition

[Kris Borer]

Fix four occurrences of the checkpatch.pl error:

ERROR: do not use assignment in if condition

Signed-off-by: Kris Borer <kborer@gmail.com>
---
 drivers/usb/core/hcd.c | 13 ++++++++-----
 1 file changed, 8 insertions(+), 5 deletions(-)

diff --git a/drivers/usb/core/hcd.c b/drivers/usb/core/hcd.c
index be5b207..e268c45 100644
--- a/drivers/usb/core/hcd.c
+++ b/drivers/usb/core/hcd.c
@@ -2683,12 +2683,13 @@ int usb_add_hcd(struct usb_hcd *hcd,
 	 * bottom up so that hcds can customize the root hubs before hub_wq
 	 * starts talking to them.  (Note, bus id is assigned early too.)
 	 */
-	if ((retval = hcd_buffer_create(hcd)) != 0) {
+	retval = hcd_buffer_create(hcd);
+	if (retval != 0) {
 		dev_dbg(hcd->self.controller, "pool alloc failed\n");
 		goto err_create_buf;
 	}
-
-	if ((retval = usb_register_bus(&hcd->self)) < 0)
+	retval = usb_register_bus(&hcd->self);
+	if (retval < 0)
 		goto err_register_bus;
 
 	rhdev = usb_alloc_dev(NULL, &hcd->self, 0);
@@ -2734,7 +2735,8 @@ int usb_add_hcd(struct usb_hcd *hcd,
 	/* "reset" is misnamed; its role is now one-time init. the controller
 	 * should already have been reset (and boot firmware kicked off etc).
 	 */
-	if (hcd->driver->reset && (retval = hcd->driver->reset(hcd)) < 0) {
+	retval = hcd->driver->reset(hcd);
+	if (hcd->driver->reset && retval < 0) {
 		dev_err(hcd->self.controller, "can't setup: %d\n", retval);
 		goto err_hcd_driver_setup;
 	}
@@ -2766,7 +2768,8 @@ int usb_add_hcd(struct usb_hcd *hcd,
 	}
 
 	/* starting here, usbcore will pay attention to this root hub */
-	if ((retval = register_root_hub(hcd)) != 0)
+	retval = register_root_hub(hcd);
+	if (retval != 0)
 		goto err_register_root_hub;
 
 	retval = sysfs_create_group(&rhdev->dev.kobj, &usb_bus_attr_group);
-- 
1.9.1

Re: [PATCH] usb: move assignment out of if condition

[Sergei Shtylyov]

Hello.

On 6/30/2015 4:02 PM, Kris Borer wrote:

> Fix four occurrences of the checkpatch.pl error:

> ERROR: do not use assignment in if condition

> Signed-off-by: Kris Borer <kborer@gmail.com>
> ---
>   drivers/usb/core/hcd.c | 13 ++++++++-----
>   1 file changed, 8 insertions(+), 5 deletions(-)

> diff --git a/drivers/usb/core/hcd.c b/drivers/usb/core/hcd.c
> index be5b207..e268c45 100644
> --- a/drivers/usb/core/hcd.c
> +++ b/drivers/usb/core/hcd.c
[...]
> @@ -2734,7 +2735,8 @@ int usb_add_hcd(struct usb_hcd *hcd,
>   	/* "reset" is misnamed; its role is now one-time init. the controller
>   	 * should already have been reset (and boot firmware kicked off etc).
>   	 */
> -	if (hcd->driver->reset && (retval = hcd->driver->reset(hcd)) < 0) {
> +	retval = hcd->driver->reset(hcd);
> +	if (hcd->driver->reset && retval < 0) {

    If hcd->driver->reset() is NULL, this change warrants a kernel oops.

[...]

WBR, Sergei

Re: [PATCH] usb: move assignment out of if condition

[Oliver Neukum]

On Tue, 2015-06-30 at 09:02 -0400, Kris Borer wrote:
> Fix four occurrences of the checkpatch.pl error:
> 
> ERROR: do not use assignment in if condition
> 
> Signed-off-by: Kris Borer <kborer@gmail.com>

Sorry, but NACK!
Those patches are totally broken.

> ---
>  drivers/usb/core/hcd.c | 13 ++++++++-----
>  1 file changed, 8 insertions(+), 5 deletions(-)
> 
> diff --git a/drivers/usb/core/hcd.c b/drivers/usb/core/hcd.c
> index be5b207..e268c45 100644
> --- a/drivers/usb/core/hcd.c
> +++ b/drivers/usb/core/hcd.c
> @@ -2683,12 +2683,13 @@ int usb_add_hcd(struct usb_hcd *hcd,
>  	 * bottom up so that hcds can customize the root hubs before hub_wq
>  	 * starts talking to them.  (Note, bus id is assigned early too.)
>  	 */
> -	if ((retval = hcd_buffer_create(hcd)) != 0) {
> +	retval = hcd_buffer_create(hcd);
> +	if (retval != 0) {
>  		dev_dbg(hcd->self.controller, "pool alloc failed\n");
>  		goto err_create_buf;
>  	}
> -
> -	if ((retval = usb_register_bus(&hcd->self)) < 0)
> +	retval = usb_register_bus(&hcd->self);
> +	if (retval < 0)
>  		goto err_register_bus;
>  
>  	rhdev = usb_alloc_dev(NULL, &hcd->self, 0);
> @@ -2734,7 +2735,8 @@ int usb_add_hcd(struct usb_hcd *hcd,
>  	/* "reset" is misnamed; its role is now one-time init. the controller
>  	 * should already have been reset (and boot firmware kicked off etc).
>  	 */
> -	if (hcd->driver->reset && (retval = hcd->driver->reset(hcd)) < 0) {
> +	retval = hcd->driver->reset(hcd);

You happily follow the NULL pointer.

	Regards
		Oliver

Re: [PATCH] usb: move assignment out of if condition

[Greg KH]

On Tue, Jun 30, 2015 at 09:02:22AM -0400, Kris Borer wrote:
> Fix four occurrences of the checkpatch.pl error:
> 
> ERROR: do not use assignment in if condition

If you are going to do stuff like this, use Coccinelle so you are sure
you don't break the code.

Also always test your changes, if possible.

greg k-h