Re: [PATCH 2/2] i3c/master: add the mipi-i3c-hci driver

Nicolas Pitre
2020-08-20T16:47:58Z

On Thu, 20 Aug 2020, Boris Brezillon wrote:

> On Thu, 20 Aug 2020 10:08:29 +0200
> Miquel Raynal <miquel.raynal@bootlin.com> wrote:
>
> > > + /*
> > > + * TODO: Extend the subsystem layer to allow for registering
> > > + * new device and provide BCR/DCR/PID at the same time.
> >
> > Not sure this is needed if you don't use it directly as the core will
> > anyway (in its current form) send the relevant CCC to read these
> > registers.
>
> We considered optimizing that in the past but that means making the DAA
> and SETDASA registration different. I'm not sure it's worth it to be
> honest, PID/DCR/BCR only happens when initializing devices and I
> suspect the overhead of querying those DATA twice in case of DAA is
> negligible anyway.

Wellllll... I know some people who do feel strongly about this
particular issue for some reasons. So I'd prefer giving them some hope
and leave the door open to some i3c_master_add_i3c_dev_and_info()
interface. In the end, it's just a matter of pre-filling the info struct
and skipping the PID retrieval in i3c_master_getpid_locked() if already
available, etc.

Nicolas