Re: [PATCH v6 net-next 1/5] net: dsa: propagate extack to ds->ops->port_hsr_join()

[Vladimir Oltean <olteanv@gmail.com>]

On Fri, Sep 22, 2023 at 03:31:04PM +0200, Lukasz Majewski wrote:
> From: Vladimir Oltean <vladimir.oltean@nxp.com>
> 
> Drivers can provide meaningful error messages which state a reason why
> they can't perform an offload, and dsa_slave_changeupper() already has
> the infrastructure to propagate these over netlink rather than printing
> to the kernel log. So pass the extack argument and modify the xrs700x
> driver's port_hsr_join() prototype.
> 
> Also take the opportunity and use the extack for the 2 -EOPNOTSUPP cases
> from xrs700x_hsr_join().
> 
> Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
> Signed-off-by: Lukasz Majewski <lukma@denx.de>
> Reviewed-by: Florian Fainelli <florian.fainelli@broadcom.com>
> ---
> Changes for v5:
> - New patch
> Changes for v6:
> - None
> ---
>  drivers/net/dsa/xrs700x/xrs700x.c | 18 ++++++++++++------
>  include/net/dsa.h                 |  3 ++-
>  net/dsa/port.c                    |  5 +++--
>  net/dsa/port.h                    |  3 ++-
>  net/dsa/slave.c                   |  2 +-
>  5 files changed, 20 insertions(+), 11 deletions(-)
> 
> diff --git a/drivers/net/dsa/xrs700x/xrs700x.c b/drivers/net/dsa/xrs700x/xrs700x.c
> index 753fef757f11..5b02e9e426fd 100644
> --- a/drivers/net/dsa/xrs700x/xrs700x.c
> +++ b/drivers/net/dsa/xrs700x/xrs700x.c
> @@ -548,7 +548,8 @@ static void xrs700x_bridge_leave(struct dsa_switch *ds, int port,
>  }
>  
>  static int xrs700x_hsr_join(struct dsa_switch *ds, int port,
> -			    struct net_device *hsr)
> +			    struct net_device *hsr,
> +			    struct netlink_ext_ack *extack)
>  {
>  	unsigned int val = XRS_HSR_CFG_HSR_PRP;
>  	struct dsa_port *partner = NULL, *dp;
> @@ -562,16 +563,21 @@ static int xrs700x_hsr_join(struct dsa_switch *ds, int port,
>  	if (ret)
>  		return ret;
>  
> -	/* Only ports 1 and 2 can be HSR/PRP redundant ports. */
> -	if (port != 1 && port != 2)
> +	if (port != 1 && port != 2) {
> +		NL_SET_ERR_MSG_MOD(extack,
> +				   "Only ports 1 and 2 can offload HSR/PRP");
>  		return -EOPNOTSUPP;
> +	}
>  
> -	if (ver == HSR_V1)
> +	if (ver == HSR_V1) {
>  		val |= XRS_HSR_CFG_HSR;
> -	else if (ver == PRP_V1)
> +	} else if (ver == PRP_V1) {
>  		val |= XRS_HSR_CFG_PRP;
> -	else
> +	} else {
> +		NL_SET_ERR_MSG_MOD(extack,
> +				   "Only HSR v1 and PRP v1 can be offloaded");
>  		return -EOPNOTSUPP;
> +	}
>  
>  	dsa_hsr_foreach_port(dp, ds, hsr) {
>  		if (dp->index != port) {
> diff --git a/include/net/dsa.h b/include/net/dsa.h
> index 0b9c6aa27047..426724808e76 100644
> --- a/include/net/dsa.h
> +++ b/include/net/dsa.h
> @@ -1198,7 +1198,8 @@ struct dsa_switch_ops {
>  	 * HSR integration
>  	 */
>  	int	(*port_hsr_join)(struct dsa_switch *ds, int port,
> -				 struct net_device *hsr);
> +				 struct net_device *hsr,
> +				 struct netlink_ext_ack *extack);
>  	int	(*port_hsr_leave)(struct dsa_switch *ds, int port,
>  				  struct net_device *hsr);
>  
> diff --git a/net/dsa/port.c b/net/dsa/port.c
> index 37ab238e8304..5f01bd4f9dec 100644
> --- a/net/dsa/port.c
> +++ b/net/dsa/port.c
> @@ -2024,7 +2024,8 @@ void dsa_shared_port_link_unregister_of(struct dsa_port *dp)
>  		dsa_shared_port_setup_phy_of(dp, false);
>  }
>  
> -int dsa_port_hsr_join(struct dsa_port *dp, struct net_device *hsr)
> +int dsa_port_hsr_join(struct dsa_port *dp, struct net_device *hsr,
> +		      struct netlink_ext_ack *extack)
>  {
>  	struct dsa_switch *ds = dp->ds;
>  	int err;
> @@ -2034,7 +2035,7 @@ int dsa_port_hsr_join(struct dsa_port *dp, struct net_device *hsr)
>  
>  	dp->hsr_dev = hsr;
>  
> -	err = ds->ops->port_hsr_join(ds, dp->index, hsr);
> +	err = ds->ops->port_hsr_join(ds, dp->index, hsr, extack);
>  	if (err)
>  		dp->hsr_dev = NULL;
>  
> diff --git a/net/dsa/port.h b/net/dsa/port.h
> index dc812512fd0e..334879964e2c 100644
> --- a/net/dsa/port.h
> +++ b/net/dsa/port.h
> @@ -103,7 +103,8 @@ int dsa_port_phylink_create(struct dsa_port *dp);
>  void dsa_port_phylink_destroy(struct dsa_port *dp);
>  int dsa_shared_port_link_register_of(struct dsa_port *dp);
>  void dsa_shared_port_link_unregister_of(struct dsa_port *dp);
> -int dsa_port_hsr_join(struct dsa_port *dp, struct net_device *hsr);
> +int dsa_port_hsr_join(struct dsa_port *dp, struct net_device *hsr,
> +		      struct netlink_ext_ack *extack);
>  void dsa_port_hsr_leave(struct dsa_port *dp, struct net_device *hsr);
>  int dsa_port_tag_8021q_vlan_add(struct dsa_port *dp, u16 vid, bool broadcast);
>  void dsa_port_tag_8021q_vlan_del(struct dsa_port *dp, u16 vid, bool broadcast);
> diff --git a/net/dsa/slave.c b/net/dsa/slave.c
> index 48db91b33390..2b3d89b77121 100644
> --- a/net/dsa/slave.c
> +++ b/net/dsa/slave.c
> @@ -2862,7 +2862,7 @@ static int dsa_slave_changeupper(struct net_device *dev,
>  		}
>  	} else if (is_hsr_master(info->upper_dev)) {
>  		if (info->linking) {
> -			err = dsa_port_hsr_join(dp, info->upper_dev);
> +			err = dsa_port_hsr_join(dp, info->upper_dev, extack);
>  			if (err == -EOPNOTSUPP) {
>  				NL_SET_ERR_MSG_WEAK_MOD(extack,
>  							"Offloading not supported");
> -- 
> 2.20.1
> 

It would have been good to Cc George here, for the driver-side patch.
But anyway, it looks ok.