Re: [PATCH v2 04/17] i3c: renesas: Reconfigure the DATBAS register on re-attach

[Frank Li]

On Tue, Jun 02, 2026 at 04:28:11PM +0300, Claudiu Beznea wrote:
> From: Claudiu Beznea <claudiu.beznea.uj@xxxxxxxxxxxxxx>
>
> During re-attach, the device may change its position in the i3c->addrs[]
> array. As a result, it may use a different Device Address Table Basic
> Register (DATBAS), which needs to be reconfigured.
>
> Reconfigure the DATBAS register on re-attach. Along with it update
> software caches.
>
> Fixes: d028219a9f14 ("i3c: master: Add basic driver for the Renesas I3C controller")
> Cc: stable@xxxxxxxxxxxxxxx
> Signed-off-by: Claudiu Beznea <claudiu.beznea.uj@xxxxxxxxxxxxxx>
> ---

Reviewed-by: Frank Li <Frank.Li@xxxxxxx>

>
> Changes in v2:
> - dropped the "if (pos < 0)" check in renesas_i3c_reattach_i3c_dev() to allow
>   re-attaching in case of a full bus; along with it the condition to update
>   the DATBAS register and software caches was updated to
>   if (data->index != pos && pos >= 0)
> - adjusted the patch title
>
>  drivers/i3c/master/renesas-i3c.c | 16 ++++++++++++++++
>  1 file changed, 16 insertions(+)
>
> diff --git a/drivers/i3c/master/renesas-i3c.c b/drivers/i3c/master/renesas-i3c.c
> index 4c86e7257804..76a4831098c9 100644
> --- a/drivers/i3c/master/renesas-i3c.c
> +++ b/drivers/i3c/master/renesas-i3c.c
> @@ -892,10 +892,26 @@ static int renesas_i3c_reattach_i3c_dev(struct i3c_dev_desc *dev,
>  	struct i3c_master_controller *m = i3c_dev_get_master(dev);
>  	struct renesas_i3c *i3c = to_renesas_i3c(m);
>  	struct renesas_i3c_i2c_dev_data *data = i3c_dev_get_master_data(dev);
> +	int pos;
> +
> +	pos = renesas_i3c_get_free_pos(i3c);
> +
> +	if (data->index != pos && pos >= 0) {
> +		renesas_writel(i3c->regs, DATBAS(data->index), 0);
> +		i3c->addrs[data->index] = 0;
> +		i3c->free_pos |= BIT(data->index);
> +
> +		data->index = pos;
> +		i3c->free_pos &= ~BIT(data->index);
> +	}
>
>  	i3c->addrs[data->index] = dev->info.dyn_addr ? dev->info.dyn_addr :
>  							dev->info.static_addr;
>
> +	renesas_writel(i3c->regs, DATBAS(data->index),
> +		       DATBAS_DVSTAD(dev->info.static_addr) |
> +		       datbas_dvdyad_with_parity(i3c->addrs[data->index]));
> +
>  	return 0;
>  }
>
> --
> 2.43.0
>