mlxbf_gige: disable RX filters until RX path initialized

A recent change to the driver exposed a bug where the MAC RX
filters (unicast MAC, broadcast MAC, and multicast MAC) are
configured and enabled before the RX path is fully initialized.
The result of this bug is that after the PHY is started packets
that match these MAC RX filters start to flow into the RX FIFO.
And then, after rx_init() is completed, these packets will go
into the driver RX ring as well. If enough packets are received
to fill the RX ring (default size is 128 packets) before the call
to request_irq() completes, the driver RX function becomes stuck.

This bug is intermittent but is most likely to be seen where the
oob_net0 interface is connected to a busy network with lots of
broadcast and multicast traffic.

All the MAC RX filters must be disabled until the RX path is ready,
i.e. all initialization is done and all the IRQs are installed.

Fixes: f7442a634ac0 ("mlxbf_gige: call request_irq() after NAPI initialized")
Reviewed-by: Asmaa Mnebhi <asmaa@nvidia.com>
Signed-off-by: David Thompson <davthompson@nvidia.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Link: https://patch.msgid.link/20240809163612.12852-1-davthompson@nvidia.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

1 files changed, 44 insertions, 6 deletions

diff --git a/drivers/net/ethernet/mellanox/mlxbf_gige/mlxbf_gige_rx.c b/drivers/net/ethernet/mellanox/mlxbf_gige/mlxbf_gige_rx.c
index 699984358493..eb62620b63c7 100644
--- a/drivers/net/ethernet/mellanox/mlxbf_gige/mlxbf_gige_rx.c
+++ b/drivers/net/ethernet/mellanox/mlxbf_gige/mlxbf_gige_rx.c
@@ -11,15 +11,31 @@
 #include "mlxbf_gige.h"
 #include "mlxbf_gige_regs.h"
 
-void mlxbf_gige_set_mac_rx_filter(struct mlxbf_gige *priv,
-				  unsigned int index, u64 dmac)
+void mlxbf_gige_enable_multicast_rx(struct mlxbf_gige *priv)
 {
 	void __iomem *base = priv->base;
-	u64 control;
+	u64 data;
 
-	/* Write destination MAC to specified MAC RX filter */
-	writeq(dmac, base + MLXBF_GIGE_RX_MAC_FILTER +
-	       (index * MLXBF_GIGE_RX_MAC_FILTER_STRIDE));
+	data = readq(base + MLXBF_GIGE_RX_MAC_FILTER_GENERAL);
+	data |= MLXBF_GIGE_RX_MAC_FILTER_EN_MULTICAST;
+	writeq(data, base + MLXBF_GIGE_RX_MAC_FILTER_GENERAL);
+}
+
+void mlxbf_gige_disable_multicast_rx(struct mlxbf_gige *priv)
+{
+	void __iomem *base = priv->base;
+	u64 data;
+
+	data = readq(base + MLXBF_GIGE_RX_MAC_FILTER_GENERAL);
+	data &= ~MLXBF_GIGE_RX_MAC_FILTER_EN_MULTICAST;
+	writeq(data, base + MLXBF_GIGE_RX_MAC_FILTER_GENERAL);
+}
+
+void mlxbf_gige_enable_mac_rx_filter(struct mlxbf_gige *priv,
+				     unsigned int index)
+{
+	void __iomem *base = priv->base;
+	u64 control;
 
 	/* Enable MAC receive filter mask for specified index */
 	control = readq(base + MLXBF_GIGE_CONTROL);
@@ -27,6 +43,28 @@ void mlxbf_gige_set_mac_rx_filter(struct mlxbf_gige *priv,
 	writeq(control, base + MLXBF_GIGE_CONTROL);
 }
 
+void mlxbf_gige_disable_mac_rx_filter(struct mlxbf_gige *priv,
+				      unsigned int index)
+{
+	void __iomem *base = priv->base;
+	u64 control;
+
+	/* Disable MAC receive filter mask for specified index */
+	control = readq(base + MLXBF_GIGE_CONTROL);
+	control &= ~(MLXBF_GIGE_CONTROL_EN_SPECIFIC_MAC << index);
+	writeq(control, base + MLXBF_GIGE_CONTROL);
+}
+
+void mlxbf_gige_set_mac_rx_filter(struct mlxbf_gige *priv,
+				  unsigned int index, u64 dmac)
+{
+	void __iomem *base = priv->base;
+
+	/* Write destination MAC to specified MAC RX filter */
+	writeq(dmac, base + MLXBF_GIGE_RX_MAC_FILTER +
+	       (index * MLXBF_GIGE_RX_MAC_FILTER_STRIDE));
+}
+
 void mlxbf_gige_get_mac_rx_filter(struct mlxbf_gige *priv,
 				  unsigned int index, u64 *dmac)
 {