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

From: Alan Stern
Date: Wed Aug 24 2022 - 10:40:55 EST


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@xxxxxxxxx>
> ---
> 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