[PATCH net 0/3] mlxsw: DCB fixes

Patches 1 and 2 fix a problem in which PAUSE frames settings are wrongly
overridden when ieee_setpfc() gets called.

Patch 3 adds a missing rollback in port's creation error path.

Ido Schimmel (3):
  mlxsw: spectrum: Do not assume PAUSE frames are disabled
  mlxsw: spectrum: Do not override PAUSE settings
  mlxsw: spectrum: Add missing DCB rollback in error path

 drivers/net/ethernet/mellanox/mlxsw/spectrum.c     |  1 +
 drivers/net/ethernet/mellanox/mlxsw/spectrum_dcb.c | 10 ++++++----
 2 files changed, 7 insertions(+), 4 deletions(-)

-- 
2.8.2

When ieee_setpfc() gets called, PAUSE frames are not necessarily
disabled on the port.

Check if PAUSE frames are disabled or enabled and configure the port's
headroom buffer accordingly.

Fixes: d81a6bdb87ce ("mlxsw: spectrum: Add IEEE 802.1Qbb PFC support")
Signed-off-by: Ido Schimmel <redacted>
---
 drivers/net/ethernet/mellanox/mlxsw/spectrum_dcb.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/drivers/net/ethernet/mellanox/mlxsw/spectrum_dcb.c b/drivers/net/ethernet/mellanox/mlxsw/spectrum_dcb.c
index 01cfb75..3c4a178 100644
--- a/drivers/net/ethernet/mellanox/mlxsw/spectrum_dcb.c
+++ b/drivers/net/ethernet/mellanox/mlxsw/spectrum_dcb.c

@@ -351,17 +351,17 @@ static int mlxsw_sp_dcbnl_ieee_setpfc(struct net_device *dev,
 				      struct ieee_pfc *pfc)
 {
 	struct mlxsw_sp_port *mlxsw_sp_port = netdev_priv(dev);
+	bool pause_en = mlxsw_sp_port_is_pause_en(mlxsw_sp_port);
 	int err;
 
-	if ((mlxsw_sp_port->link.tx_pause || mlxsw_sp_port->link.rx_pause) &&
-	    pfc->pfc_en) {
+	if (pause_en && pfc->pfc_en) {
 		netdev_err(dev, "PAUSE frames already enabled on port\n");
 		return -EINVAL;
 	}
 
 	err = __mlxsw_sp_port_headroom_set(mlxsw_sp_port, dev->mtu,
 					   mlxsw_sp_port->dcb.ets->prio_tc,
-					   false, pfc);
+					   pause_en, pfc);
 	if (err) {
 		netdev_err(dev, "Failed to configure port's headroom for PFC\n");
 		return err;

@@ -380,7 +380,7 @@ static int mlxsw_sp_dcbnl_ieee_setpfc(struct net_device *dev,
 
 err_port_pfc_set:
 	__mlxsw_sp_port_headroom_set(mlxsw_sp_port, dev->mtu,
-				     mlxsw_sp_port->dcb.ets->prio_tc, false,
+				     mlxsw_sp_port->dcb.ets->prio_tc, pause_en,
 				     mlxsw_sp_port->dcb.pfc);
 	return err;
 }

-- 
2.8.2

We correctly execute mlxsw_sp_port_dcb_fini() when port is removed, but
I missed its rollback in the error path of port creation, so add it.

Fixes: f00817df2b42 ("mlxsw: spectrum: Introduce support for Data Center Bridging (DCB)")
Signed-off-by: Ido Schimmel <redacted>
---
 drivers/net/ethernet/mellanox/mlxsw/spectrum.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/net/ethernet/mellanox/mlxsw/spectrum.c b/drivers/net/ethernet/mellanox/mlxsw/spectrum.c
index c3e6150..e1b8f62 100644
--- a/drivers/net/ethernet/mellanox/mlxsw/spectrum.c
+++ b/drivers/net/ethernet/mellanox/mlxsw/spectrum.c

@@ -2220,6 +2220,7 @@ err_port_vlan_init:
 err_core_port_init:
 	unregister_netdev(dev);
 err_register_netdev:
+	mlxsw_sp_port_dcb_fini(mlxsw_sp_port);
 err_port_dcb_init:
 err_port_ets_init:
 err_port_buffers_init:

-- 
2.8.2

The PFCC register is used to configure both PAUSE and PFC frames.
Therefore, when PFC frames are disabled we must make sure we don't
mistakenly also disable PAUSE frames (which might be enabled).

Fix this by packing the PFCC register with the current PAUSE settings.

Note that this register is also accessed via ethtool ops, but there we
are guaranteed to have PFC disabled.

Fixes: d81a6bdb87ce ("mlxsw: spectrum: Add IEEE 802.1Qbb PFC support")
Signed-off-by: Ido Schimmel <redacted>
---
 drivers/net/ethernet/mellanox/mlxsw/spectrum_dcb.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/net/ethernet/mellanox/mlxsw/spectrum_dcb.c b/drivers/net/ethernet/mellanox/mlxsw/spectrum_dcb.c
index 3c4a178..b6ed7f7 100644
--- a/drivers/net/ethernet/mellanox/mlxsw/spectrum_dcb.c
+++ b/drivers/net/ethernet/mellanox/mlxsw/spectrum_dcb.c

@@ -341,6 +341,8 @@ static int mlxsw_sp_port_pfc_set(struct mlxsw_sp_port *mlxsw_sp_port,
 	char pfcc_pl[MLXSW_REG_PFCC_LEN];
 
 	mlxsw_reg_pfcc_pack(pfcc_pl, mlxsw_sp_port->local_port);
+	mlxsw_reg_pfcc_pprx_set(pfcc_pl, mlxsw_sp_port->link.rx_pause);
+	mlxsw_reg_pfcc_pptx_set(pfcc_pl, mlxsw_sp_port->link.tx_pause);
 	mlxsw_reg_pfcc_prio_pack(pfcc_pl, pfc->pfc_en);
 
 	return mlxsw_reg_write(mlxsw_sp_port->mlxsw_sp->core, MLXSW_REG(pfcc),

-- 
2.8.2

Thu, Aug 04, 2016 at 04:36:20PM CEST, idosch@mellanox.com wrote:

When ieee_setpfc() gets called, PAUSE frames are not necessarily
disabled on the port.

Check if PAUSE frames are disabled or enabled and configure the port's
headroom buffer accordingly.

Fixes: d81a6bdb87ce ("mlxsw: spectrum: Add IEEE 802.1Qbb PFC support")
Signed-off-by: Ido Schimmel <redacted>

Reviewed-by: Jiri Pirko <redacted>

Thu, Aug 04, 2016 at 04:36:21PM CEST, idosch@mellanox.com wrote:

The PFCC register is used to configure both PAUSE and PFC frames.
Therefore, when PFC frames are disabled we must make sure we don't
mistakenly also disable PAUSE frames (which might be enabled).

Fix this by packing the PFCC register with the current PAUSE settings.

Note that this register is also accessed via ethtool ops, but there we
are guaranteed to have PFC disabled.

Fixes: d81a6bdb87ce ("mlxsw: spectrum: Add IEEE 802.1Qbb PFC support")
Signed-off-by: Ido Schimmel <redacted>

Reviewed-by: Jiri Pirko <redacted>

Thu, Aug 04, 2016 at 04:36:22PM CEST, idosch@mellanox.com wrote:

We correctly execute mlxsw_sp_port_dcb_fini() when port is removed, but
I missed its rollback in the error path of port creation, so add it.

Fixes: f00817df2b42 ("mlxsw: spectrum: Introduce support for Data Center Bridging (DCB)")
Signed-off-by: Ido Schimmel <redacted>

Reviewed-by: Jiri Pirko <redacted>