Re: [PATCH v6 00/10] Add the I3C subsystem

[Geert Uytterhoeven]

Hi Arnd,

On Tue, Jul 24, 2018 at 5:40 PM Arnd Bergmann <arnd@xxxxxxxx> wrote:
> On Tue, Jul 24, 2018 at 5:15 PM, Geert Uytterhoeven
> <geert@xxxxxxxxxxxxxx> wrote:
> > On Tue, Jul 24, 2018 at 5:05 PM Arnd Bergmann <arnd@xxxxxxxx> wrote:
>
> >> That's not the case I was describing here, I was thinking of what
> >> Wolfram described with the Renesas SoC that has two i2c masters
> >> multiplexed through the pinmux layer. I would assume that we
> >> can still do the same thing in i3c by shutting down the current
> >> master without a handover, and reprobing everything from scratch.
> >
> > The major disadvantage of reprobing is that it may cause visual disturbances
> > when i2c slaves are involved with e.g. the display pipeline (think HDMI encoders
> > etc.).
>
> Do you mean we should reuse the device pointer and association with
> the driver even when we switch out the i3c master using the pinmux?
>
> Or do you mean we need to be prepared for driving a single
> slave through multiple masters over the lifetime of that device,
> but using the i3c master handover protocol?
> In the second case, how do we decide which master to use
> for accessing a device for a given request?

I'll have to defer to Wolfram. He's the i2c and muxing expert.

Gr{oetje,eeting}s,

                        Geert

-- 
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@xxxxxxxxxxxxxx

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                -- Linus Torvalds