On Wed. 16 mars 2022 at 02:25, Greg Kroah-Hartman
<gregkh@xxxxxxxxxxxxxxxxxxx> wrote:
> On Sun, Mar 06, 2022 at 04:55:17PM +0900, Vincent Mailhol wrote:
> > This is a transitional patch with the goal of changing the prototype
> > of usb_maxpacket() from:
> > | static inline __u16
> > | usb_maxpacket(struct usb_device *udev, int pipe, int is_out)
> >
> > into:
> > | static inline u16 usb_maxpacket(struct usb_device *dev, int pipe)
> >
> > The third argument of usb_maxpacket(): is_out gets removed because it
> > can be derived from its second argument: pipe using
> > usb_pipeout(pipe). Furthermore, in the current version,
> > ubs_pipeout(pipe) is called regardless in order to sanitize the is_out
> > parameter.
> >
> > In order to make a smooth change, we first deprecate the is_out
> > parameter by simply ignoring it (using a variadic function) and will
> > remove it latter, once all the callers get updated.
> >
> > Finally, the body of the function is reworked in order not to reinvent
> > the wheel and just relies on the usb_pipe_endpoint() helper function
> > instead.
> >
> > Signed-off-by: Vincent Mailhol <mailhol.vincent@xxxxxxxxxx>
> > ---
> > include/linux/usb.h | 24 +++---------------------
> > 1 file changed, 3 insertions(+), 21 deletions(-)
> >
> > diff --git a/include/linux/usb.h b/include/linux/usb.h
> > index 200b7b79acb5..588aa7dc3d10 100644
> > --- a/include/linux/usb.h
> > +++ b/include/linux/usb.h
> > @@ -1969,30 +1969,12 @@ usb_pipe_endpoint(struct usb_device *dev, unsigned int pipe)
> > return eps[usb_pipeendpoint(pipe)];
> > }
> >
> > -/*-------------------------------------------------------------------------*/
> > -
> > -static inline __u16
> > -usb_maxpacket(struct usb_device *udev, int pipe, int is_out)
> > +static inline u16 usb_maxpacket(struct usb_device *dev, int pipe,
> > + /* int is_out deprecated */ ...)
>
> No need to change from udev->dev, right?
Right. The motivation of this change was to align with other functions
(the majority of the functions in linux/usb.h name it dev, not udev).
Comment taken, I will keep the udev name in v3.
> > {
> > - struct usb_host_endpoint *ep;
> > - unsigned epnum = usb_pipeendpoint(pipe);
> > -
> > - if (is_out) {
> > - WARN_ON(usb_pipein(pipe));
> > - ep = udev->ep_out[epnum];
> > - } else {
> > - WARN_ON(usb_pipeout(pipe));
> > - ep = udev->ep_in[epnum];
> > - }
> > - if (!ep)
> > - return 0;
> > -
> > - /* NOTE: only 0x07ff bits are for packet size... */
> > - return usb_endpoint_maxp(&ep->desc);
> > + return usb_endpoint_maxp(&usb_pipe_endpoint(dev, pipe)->desc);
>
> The change to use usb_pipe_endpoint() can be done separately.
>
> Let's make these in tiny steps so that we can easily roll things back if
> things are not working.
ACK. I will respin the patch series as below:
* Make usb_maxpacket variadic
* Migrate the callers of usb_maxpacket()
* Suppress the third argument of usb_maxpacket()
* Change the body of usb_maxpacket() using usb_pipe_endpoint().
> thanks,
>
> greg k-h
