Re: [PATCH v4 2/6] i3c: master: pre-reserve boardinfo->init_dyn_addr when available

Przemysław Gaj
2019-12-11T08:52:01Z

Hi Vitor,

The 12/10/2019 15:24, Vitor Soares wrote:
>
> Hi Przemysław,
>
> From: Przemysław Gaj <pgaj@cadence.com>
> Date: Tue, Dec 10, 2019 at 10:14:58
>
> > It may be the case that SETDASA fails for some reason. Reserve
> > ->init_dyn_addr when it's defined to prevent assigning this address
> > to another slave device. This way when device shows up we don't
> > have to re-assign addresses.
> >
> > Signed-off-by: Przemysław Gaj <pgaj@cadence.com>
> > ---
> > drivers/i3c/master.c | 8 +++++++-
> > 1 file changed, 7 insertions(+), 1 deletion(-)
> >
> > diff --git a/drivers/i3c/master.c b/drivers/i3c/master.c
> > index 5c06c41e6660..fab6e0609fca 100755
> > --- a/drivers/i3c/master.c
> > +++ b/drivers/i3c/master.c
> > @@ -1263,7 +1263,8 @@ static void i3c_master_put_i3c_addrs(struct i3c_dev_desc *dev)
> > I3C_ADDR_SLOT_FREE);
> >
> > if (dev->boardinfo && dev->boardinfo->init_dyn_addr)
> > - i3c_bus_set_addr_slot_status(&master->bus, dev->info.dyn_addr,
> > + i3c_bus_set_addr_slot_status(&master->bus,
> > + dev->boardinfo->init_dyn_addr,
> > I3C_ADDR_SLOT_FREE);
> > }
> >
> > @@ -1675,6 +1676,11 @@ static int i3c_master_bus_init(struct i3c_master_controller *master)
> > ret = -EBUSY;
> > goto err_detach_devs;
> > }
> > +
> > + /* Reserve the slot. */
> > + i3c_bus_set_addr_slot_status(&master->bus,
> > + i3cboardinfo->init_dyn_addr,
> > + I3C_ADDR_SLOT_I3C_DEV);
> > }
> >
> > i3cdev = i3c_master_alloc_i3c_dev(master, &info);
> > --
> > 2.14.0
>
> In my experience we should pre-reserve all DT DA entries and not use them
> during the ENTDAA for safety reasons.
> That would be one of my next steps in this patch series.

Actually, I reserve DT DA address above. The only thing I will rework, I
won't free up the address. That will be documented in the code.

We can rework it later if really needed.

>
> Best regards,
> Vitor Soares
>

--
--
Regards,
Przemek