Re: [PATCH net-next v6 2/9] net: dsa: microchip: Decorrelate IRQ domain from port

[Vladimir Oltean <olteanv@gmail.com>]

On Wed, Mar 04, 2026 at 11:18:53AM +0100, Bastien Curutchet (Schneider Electric) wrote:
> KSZ8463 has one register holding interrupt bits from both port 1 and 2.
> So it has to use one IRQ domain for both of its ports. This conflicts
> with the current initialization procedure that ties one IRQ domain to
> each port.
> 
> Decorrelate IRQ domain from port so a port can use an IRQ domain not
> directly related to itself.
> 
> Signed-off-by: Bastien Curutchet (Schneider Electric) <bastien.curutchet@bootlin.com>
> ---
>  drivers/net/dsa/microchip/ksz_ptp.c | 8 ++++----
>  1 file changed, 4 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/net/dsa/microchip/ksz_ptp.c b/drivers/net/dsa/microchip/ksz_ptp.c
> index 4a2cc57a628f97bd51fcb11057bc4effda9205dd..64afe92a3479ec87b5afc66e489b92787a0fc715 100644
> --- a/drivers/net/dsa/microchip/ksz_ptp.c
> +++ b/drivers/net/dsa/microchip/ksz_ptp.c
> @@ -1099,18 +1099,18 @@ static void ksz_ptp_msg_irq_free(struct ksz_port *port, u8 n)
>  	irq_dispose_mapping(ptpmsg_irq->num);
>  }
>  
> -static int ksz_ptp_msg_irq_setup(struct ksz_port *port, u8 n)
> +static int ksz_ptp_msg_irq_setup(struct irq_domain *domain,
> +				 struct ksz_port *port, u8 n)
>  {
>  	u16 ts_reg[] = {REG_PTP_PORT_PDRESP_TS, REG_PTP_PORT_XDELAY_TS,
>  			REG_PTP_PORT_SYNC_TS};
>  	static const char * const name[] = {"pdresp-msg", "xdreq-msg",
>  					    "sync-msg"};
>  	const struct ksz_dev_ops *ops = port->ksz_dev->dev_ops;
> -	struct ksz_irq *ptpirq = &port->ptpirq;
>  	struct ksz_ptp_irq *ptpmsg_irq;
>  
>  	ptpmsg_irq = &port->ptpmsg_irq[n];
> -	ptpmsg_irq->num = irq_create_mapping(ptpirq->domain, n);
> +	ptpmsg_irq->num = irq_create_mapping(domain, n);

Looking at this function, I think there's a pre-existing bug.
If request_threaded_irq() later fails, irq_dispose_mapping() needs to be
called, because ksz_ptp_msg_irq_free() only frees the IRQ domains that
were already successfully set up.

>  	if (!ptpmsg_irq->num)
>  		return -EINVAL;
>  
> @@ -1162,7 +1162,7 @@ int ksz_ptp_irq_setup(struct dsa_switch *ds, u8 p)
>  		goto out;
>  
>  	for (irq = 0; irq < ptpirq->nirqs; irq++) {
> -		ret = ksz_ptp_msg_irq_setup(port, irq);
> +		ret = ksz_ptp_msg_irq_setup(ptpirq->domain, port, irq);
>  		if (ret)
>  			goto out_ptp_msg;
>  	}
> 
> -- 
> 2.53.0
>