Re: [PATCH v2] i3c: dw-i3c-master: Set SIR_REJECT in DAT on device attach and reattach

[Frank Li]

On Fri, Feb 13, 2026 at 02:00:48PM +0800, adrianhoyin.ng@xxxxxxxxxx wrote:
> From: Adrian Ng Ho Yin <adrianhoyin.ng@xxxxxxxxxx>
>
> The DesignWare I3C master controller ACKs IBIs as soon as a valid
> Device Address Table (DAT) entry is present. This can create a race
> between device attachment (after DAA) and the point where the client
> driver enables IBIs via i3c_device_enable_ibi().
>
> Set DEV_ADDR_TABLE_SIR_REJECT in the DAT entry during
> attach_i3c_dev() and reattach_i3c_dev() so that IBIs are rejected
> by default. The bit is managed thereafter by the existing
> dw_i3c_master_set_sir_enabled() function, which clears it in
> enable_ibi() after ENEC is issued, and restores it in disable_ibi()
> after DISEC.
>
> Fixes: 1dd728f5d4d4 ("i3c: master: Add driver for Synopsys DesignWare IP")
> Signed-off-by: Adrian Ng Ho Yin <adrianhoyin.ng@xxxxxxxxxx>
Reviewed-by: Frank Li <Frank.Li@xxxxxxx>
>
> ---
> changelog:
> v1->v2:
> * Update commit message for better clarity on SIR_REJECT bit clear upon
>   enable ibi call.
> * Add Fixes tag.
>
> ---
>  drivers/i3c/master/dw-i3c-master.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/i3c/master/dw-i3c-master.c b/drivers/i3c/master/dw-i3c-master.c
> index 7eb09ad10171..d014f2cd6071 100644
> --- a/drivers/i3c/master/dw-i3c-master.c
> +++ b/drivers/i3c/master/dw-i3c-master.c
> @@ -1024,7 +1024,7 @@ static int dw_i3c_master_reattach_i3c_dev(struct i3c_dev_desc *dev,
>  		master->free_pos &= ~BIT(pos);
>  	}
>
> -	writel(DEV_ADDR_TABLE_DYNAMIC_ADDR(dev->info.dyn_addr),
> +	writel(DEV_ADDR_TABLE_DYNAMIC_ADDR(dev->info.dyn_addr) | DEV_ADDR_TABLE_SIR_REJECT,
>  	       master->regs +
>  	       DEV_ADDR_TABLE_LOC(master->datstartaddr, data->index));
>
> @@ -1053,7 +1053,7 @@ static int dw_i3c_master_attach_i3c_dev(struct i3c_dev_desc *dev)
>  	master->free_pos &= ~BIT(pos);
>  	i3c_dev_set_master_data(dev, data);
>
> -	writel(DEV_ADDR_TABLE_DYNAMIC_ADDR(master->devs[pos].addr),
> +	writel(DEV_ADDR_TABLE_DYNAMIC_ADDR(master->devs[pos].addr) | DEV_ADDR_TABLE_SIR_REJECT,
>  	       master->regs +
>  	       DEV_ADDR_TABLE_LOC(master->datstartaddr, data->index));
>
> --
> 2.49.GIT
>