Re: [PATCH 3/4] USB: serial: add support for multi-interface functions

From: Oliver Neukum
Date: Thu Apr 08 2021 - 06:11:04 EST


Am Donnerstag, den 01.04.2021, 09:46 +0200 schrieb Johan Hovold:
> On Wed, Mar 31, 2021 at 01:21:15PM +0200, Oliver Neukum wrote:
> > Am Mittwoch, den 31.03.2021, 09:08 +0200 schrieb Oliver Neukum:

> > on the third hand, the more I look at this, would you mind putting
> > sibling_release() with a modified name into usbcore? This functionality
> > is not limited to serial drivers. btusb needs it; cdc-acm needs it;
> > usbaudio neds it. We have code duplication.
>
> Tell me about it. ;) Unfortunately, drivers all tend to handle this
> slightly different, for example, using a disconnected flag, some claim
> more than one other interface, others look like they may be using their
> interface data as a flag for other purposes, etc.
>
> At some point we could unify all this but until then I don't think
> putting only half of an interface into core makes much sense.

OK, very well, then let's look at this from a fundamental point
and design a bit. First, can we disregard the case of more than
two interfaces?

Regards
Oliver