Re: [PATCH v4 0/9] usb: rework usb_maxpacket() and remove its third argument

From: Vincent MAILHOL <mailhol.vincent@wanadoo.fr>
To: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: linux-usb@vger.kernel.org
Subject: Re: [PATCH v4 0/9] usb: rework usb_maxpacket() and remove its third argument
Date: Fri, 22 Apr 2022 23:00:35 +0900	[thread overview]
Message-ID: <CAMZ6RqKhJ5aypM+dBF38nL626PDdD-gr2AHJz1ozpov+OSzbAw@mail.gmail.com> (raw)
In-Reply-To: <YmKv37an0DR7/iPE@kroah.com>

On Fri. 22 Apr. 2022 at 22:38, Greg Kroah-Hartman
<gregkh@linuxfoundation.org> wrote:
> On Thu, Mar 17, 2022 at 12:55:05PM +0900, Vincent Mailhol wrote:
> > This series rework usb_maxpacket() to change its prototype from:
> > | static inline __u16
> > | usb_maxpacket(struct usb_device *udev, int pipe, int is_out)
> >
> > into:
> > | static inline u16 usb_maxpacket(struct usb_device *udev, int pipe)
> >
> > and rewrite the function using usb_pipe_endpoint().
> >
> > Rationale:
> >
> >   * The third argument of usb_maxpacket(): is_out can be derived from
> >     its second one: pipe using usb_pipeout(pipe). Furthermore,
> >     usb_pipeout(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.
> >
> >   * usb_pipe_endpoint() (defined a couple of lines before) does most
> >     of the work. Use it instead of reimplementing the same thing
> >     again.
> >
> > In order to do so, usb_maxpacket() is temporarily changed into a variadic
> > function to ignore its third argument.
> >
> > The series goes as follow:
> >
> >     * Patch 1: make usb_maxpacket() variadic to accommodate during the
> >       migration
> >
> >     * Patch 2 to 7: migrate all the users of usb_maxpacket() (one
> >       patch per tree)
> >
> >     * Patch 8: remove the third argument of usb_maxpacket() now that
> >       everyone is migrated
> >
> >     * Patch 9: rework usb_maxpacket()'s body using usb_pipe_endpoint()
>
> Now queued up, thanks for sticking with this!

Thanks to you for your patience and explanations!

> Can you send the follow-up patch that removes the vararg?  I'll keep
> that in my tree to try to catch any remaining things that come in and
> get it merged when it's ok to.

It is this patch:
https://lore.kernel.org/linux-usb/20220317035514.6378-9-mailhol.vincent@wanadoo.fr/

Or do you prefer me to resend it on the mailing list?

Yours sincerely,
Vincent Mailhol