<Removed people in CC>
On Fri. 4 Mar. 2022 at 23:20, Greg Kroah-Hartman
<gregkh@xxxxxxxxxxxxxxxxxxx> wrote:
> On Fri, Mar 04, 2022 at 07:53:50PM +0900, Vincent Mailhol wrote:
> > Change 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)
> >
> > and rewrite the function.
> >
> > Rationale:
> >
> > * The third argument of usb_maxpacket(): is_out can be derived from
> > its second one: pipe using usb_pipeout(pipe). Furthermore,
> > usb_pipoout(pipe) is being called within usb_maxpacket()
> > regardless to confirm the input.
> >
> > * This function is not exposed to the UAPI so return type should be
> > u16, not __u16.
> >
> > * Let's not reinvent the wheel and rely on usb_endpoint_maxp() to
> > make this a one liner function.
> >
> > All the users of usb_endpoint_maxp() are then updated.
> >
> > Two of the users: oxu210hp-hcd.c and isp1760-hcd.c rely on a local
> > macro: max_packet() to mask the maximum size. Because this masking is
> > already performed by usb_maxpacket(), this patch also removes these
> > redundant sanitization and remove the local macro if not needed any
> > more (keep it in oxu210hp-hcd.c which uses it elsewhere but remove it
> > in isp1760-hcd.c).
>
> This type of "change all callers of this function" is brutal to do like
> this, as is evident by the number of people you had to cc: here.
>
> How about doing it the normal way. Create a new function, with the
> proper options you wish to see be used, and then move everyone over to
> it, and when that is done, remove the old function. Bonus points for
> doing this with some crazy macros to keep the old name in the end (it
> can be done, but I don't recommend it for the faint-of-heart, so it's
> not required.)
Thank you for the explanation :)
If I understand correctly, I should:
* First change linux/usb.h
* Wait for other trees to pull the patch
* Change the drivers
* Clean up linux/usb.h
I did not find the inspiration for a better name so I would like to
keep the old one.
Would the below code meet your expectation of "doing some crazy macros"?
| static inline u16 __usb_maxpacket(struct usb_device *dev, int pipe)
| {
| return usb_endpoint_maxp(&usb_pipe_endpoint(dev, pipe)->desc);
| }
|
| #define usb_maxpacket(dev, pipe, deprecated...) __usb_maxpacket(dev, pipe)
Thank you,
Yours sincerely,
Vincent Mailhol
