Re: [PATCH] usb: host: Use helper function to get endpoint

[Alan Stern <stern@rowland.harvard.edu>]

On Wed, Aug 24, 2022 at 07:07:02PM +0600, Khalid Masum wrote:
> Current implementation to convert urb pipe number to struct 
> usb_host_endpoint in rquest_single_step_set_feature_urb is a little
> messy. 
> 
> Use usb_pipe_endpoint helper function to get the endpoint instead.
> 
> Signed-off-by: Khalid Masum <khalid.masum.92@gmail.com>
> ---
>  drivers/usb/core/hcd.c | 3 +--
>  1 file changed, 1 insertion(+), 2 deletions(-)
> 
> diff --git a/drivers/usb/core/hcd.c b/drivers/usb/core/hcd.c
> index 94b305bbd621..107e29d5d3ae 100644
> --- a/drivers/usb/core/hcd.c
> +++ b/drivers/usb/core/hcd.c
> @@ -2165,8 +2165,7 @@ static struct urb *request_single_step_set_feature_urb(
>  		return NULL;
>  
>  	urb->pipe = usb_rcvctrlpipe(udev, 0);
> -	ep = (usb_pipein(urb->pipe) ? udev->ep_in : udev->ep_out)
> -				[usb_pipeendpoint(urb->pipe)];
> +	ep = usb_pipe_endpoint(udev, urb->pipe);
>  	if (!ep) {
>  		usb_free_urb(urb);
>  		return NULL;

Even this is awkward.  It's silly to look up the endpoint in a table 
when you already know that it is endpoint 0.  Just do:

	ep = &udev->ep0;

with no need to check for NULL.

Alan Stern