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