| Message ID | 20220824130702.10912-1-khalid.masum.92@gmail.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | usb: host: Use helper function to get endpoint | expand |
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
On Wed, Aug 24, 2022 at 8:40 PM Alan Stern <stern@rowland.harvard.edu> wrote: > > On Wed, Aug 24, 2022 at 07:07:02PM +0600, Khalid Masum wrote: > > ep = &udev->ep0; > > with no need to check for NULL. Thanks, I shall send a v2 with this change. > Alan Stern -- Khalid Masum
On Wed, Aug 24, 2022 at 8:40 PM Alan Stern <stern@rowland.harvard.edu> wrote: > > > 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. After further checking, I realized that usb_device udev is created by ehset_single_step_set_feature and depends on usb_hcd and port. So I do not get why the endpoint is at udev->ep0. Can you help me with this? -- Khalid Masum
On Wed, Aug 24, 2022 at 11:57:25PM +0600, Khalid Masum wrote: > On Wed, Aug 24, 2022 at 8:40 PM Alan Stern <stern@rowland.harvard.edu> wrote: > > > > > > 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. > > After further checking, I realized that usb_device udev is created by > ehset_single_step_set_feature and depends on usb_hcd and port. So I do > not get why the endpoint is at udev->ep0. Can you help me with this? udev is not a usb_device structure; it is a _pointer_ to a usb_device structure. The pointer is created when ehset_single_step_set_feature() calls usb_hub_find_child(), but the structure itself gets created long before that, when the USB device is first detected and initialized. You can see this happening where hub_port_connect() calls usb_alloc_dev(). The ep0 field is filled in by hub_port_init() and the routines it calls. Alan Stern
On Thu, Aug 25, 2022 at 1:24 AM Alan Stern <stern@rowland.harvard.edu> wrote: > > udev is not a usb_device structure; it is a _pointer_ to a usb_device > structure. The pointer is created when ehset_single_step_set_feature() > calls usb_hub_find_child(), but the structure itself gets created long > before that, when the USB device is first detected and initialized. > > You can see this happening where hub_port_connect() calls > usb_alloc_dev(). The ep0 field is filled in by hub_port_init() and the > routines it calls. > Thanks for clarifying this. That helps a lot. -- Khalid Masum
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;
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(-)