From: Stefan Eichenberger <stefan.eichenberger@toradex.com>

The usb_sndaddr0pipe macro is only used in the hub_set_address function.
Replace it with usb_sndctrlpipe which provides the same functionality
but would also consider the endpoint device number.

If the device has not been initialised, it is safe to use
usb_sndctrlpipe in this context because udev->devnum is set to 0.
Therefore, this change does not affect behaviour, but reduces code
complexity by reusing the existing macro.

Signed-off-by: Stefan Eichenberger <stefan.eichenberger@toradex.com>
---
Even though this patch does not fix a bug it is related to the following
discussion and addresses the change proposed by Alan:
https://lore.kernel.org/all/aa0c06f6-f997-4bcf-a5a3-6b17f6355fca@rowland.harvard.edu/
---
 drivers/usb/core/hub.c | 4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c
index 59e38780f76d0..66dfdf0bab90b 100644
--- a/drivers/usb/core/hub.c
+++ b/drivers/usb/core/hub.c
@@ -4697,8 +4697,6 @@ void usb_ep0_reinit(struct usb_device *udev)
 }
 EXPORT_SYMBOL_GPL(usb_ep0_reinit);
 
-#define usb_sndaddr0pipe()	(PIPE_CONTROL << 30)
-
 static int hub_set_address(struct usb_device *udev, int devnum)
 {
 	int retval;
@@ -4722,7 +4720,7 @@ static int hub_set_address(struct usb_device *udev, int devnum)
 	if (hcd->driver->address_device)
 		retval = hcd->driver->address_device(hcd, udev, timeout_ms);
 	else
-		retval = usb_control_msg(udev, usb_sndaddr0pipe(),
+		retval = usb_control_msg(udev, usb_sndctrlpipe(udev, 0),
 				USB_REQ_SET_ADDRESS, 0, devnum, 0,
 				NULL, 0, timeout_ms);
 	if (retval == 0) {
-- 
2.45.2

On Wed, Feb 19, 2025 at 09:36:44AM +0100, Stefan Eichenberger wrote:
> From: Stefan Eichenberger <stefan.eichenberger@toradex.com>
> 
> The usb_sndaddr0pipe macro is only used in the hub_set_address function.
> Replace it with usb_sndctrlpipe which provides the same functionality
> but would also consider the endpoint device number.
> 
> If the device has not been initialised, it is safe to use
> usb_sndctrlpipe in this context because udev->devnum is set to 0.
> Therefore, this change does not affect behaviour, but reduces code
> complexity by reusing the existing macro.
> 
> Signed-off-by: Stefan Eichenberger <stefan.eichenberger@toradex.com>
> ---
> Even though this patch does not fix a bug it is related to the following
> discussion and addresses the change proposed by Alan:
> https://lore.kernel.org/all/aa0c06f6-f997-4bcf-a5a3-6b17f6355fca@rowland.harvard.edu/
> ---

Acked-by: Alan Stern <stern@rowland.harvard.edu>

>  drivers/usb/core/hub.c | 4 +---
>  1 file changed, 1 insertion(+), 3 deletions(-)
> 
> diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c
> index 59e38780f76d0..66dfdf0bab90b 100644
> --- a/drivers/usb/core/hub.c
> +++ b/drivers/usb/core/hub.c
> @@ -4697,8 +4697,6 @@ void usb_ep0_reinit(struct usb_device *udev)
>  }
>  EXPORT_SYMBOL_GPL(usb_ep0_reinit);
>  
> -#define usb_sndaddr0pipe()	(PIPE_CONTROL << 30)
> -
>  static int hub_set_address(struct usb_device *udev, int devnum)
>  {
>  	int retval;
> @@ -4722,7 +4720,7 @@ static int hub_set_address(struct usb_device *udev, int devnum)
>  	if (hcd->driver->address_device)
>  		retval = hcd->driver->address_device(hcd, udev, timeout_ms);
>  	else
> -		retval = usb_control_msg(udev, usb_sndaddr0pipe(),
> +		retval = usb_control_msg(udev, usb_sndctrlpipe(udev, 0),
>  				USB_REQ_SET_ADDRESS, 0, devnum, 0,
>  				NULL, 0, timeout_ms);
>  	if (retval == 0) {
> -- 
> 2.45.2
>