Re: [PATCH v6 01/10] i3c: Add core I3C infrastructure
From: Boris Brezillon
Date: Tue Aug 28 2018 - 09:01:20 EST
On Tue, 28 Aug 2018 12:55:20 +0000
Przemyslaw Gaj <pgaj@xxxxxxxxxxx> wrote:
> Hi Vitor,
> I have already implemented Mastership request/handover but we are waiting for Borisâs patch to be accepted and merged. Anyway, my comments below.
> ïOn 8/28/18, 2:02 PM, "Boris Brezillon" <boris.brezillon@xxxxxxxxxxx> wrote:
> EXTERNAL MAIL
> Hi Vitor,
> On Tue, 28 Aug 2018 12:50:12 +0100
> vitor <Vitor.Soares@xxxxxxxxxxxx> wrote:
> > Hi Boris,
> > The DT Bindings say "The node describing an I3C bus should be named
> > i3c-master.". Do you have a field for secondary master?
> I think we donât need separate field for secondary master. Main and secondary masters
> support similar functionalities. Itâs enough to have this state internally and do mastership it it's needed.
> > On 24-08-2018 19:16, Boris Brezillon wrote:
> > > Well, before even considering supporting secondary master registration,
> > > we need to handle mastership handover. As for the DAA operation, it's
> > > likely to be host specific, so we'll have to add a new hook to the
> > > i3c_master_controller_ops struct.
> > Do you mean when master try to delegate the bus ownership through
> > GETACCMST? or to get the bus ownership with IBI-MR?
> I think we need to support both.
> I agree.
> > I think that could be useful to pass the ibi type on request_ibi(),
> > there is some case where the master doesn't support IBI-MR.
> Actually, I was planning on making it completely separate from
> regular slave IBIs. That is, the master controller driver would demux
> the slave, MR and Hot Join IBIs, and if there's an MR request, queue a
> mastership handover work to the workqueue (pretty much what we do for
> Hot-Join already). Mastership handover is anyway likely to be IP
> specific, so I don't think there's a need to make it look like a
> regular IBI.
> I think it's better to have separate function to do mastership request.
> Regarding whether IBI-MR support should be exposed to the I3C framework
> or not depends on how much will be automated on the framework side. I
> don't the answer yet, but that's probably something will figure out
> along the road.
> My current implementation is: when request_mastership field
> of i3c_master_controller_ops structure is set, master driver supports mastership requests.
> That's how I check if this is supported or not.
Can you maybe host your code on a public repo (I can push it for you if
needed) so that you and Vitor can start discussing implementation