[PATCH net 4/4] net: bcmgenet: restore the Tx coalescing setting when the rings are rebuilt

[Nicolai Buchwitz]

bcmgenet_set_coalesce() writes tx_max_coalesced_frames straight into
DMA_MBUF_DONE_THRESH and keeps no copy of it, while
bcmgenet_init_tx_ring() programs a fixed 1. An ifdown and ifup or a resume
then puts the Tx coalescing back to one frame per interrupt.

Rx keeps its value per ring and reapplies it on init. Do the same for Tx.

Fixes: 2f9130709d2c ("net: bcmgenet: Implement TX coalescing control knobs")
Signed-off-by: Nicolai Buchwitz <nb@xxxxxxxxxxx>
---
 drivers/net/ethernet/broadcom/genet/bcmgenet.c | 10 ++++++++--
 drivers/net/ethernet/broadcom/genet/bcmgenet.h |  1 +
 2 files changed, 9 insertions(+), 2 deletions(-)

diff --git a/drivers/net/ethernet/broadcom/genet/bcmgenet.c b/drivers/net/ethernet/broadcom/genet/bcmgenet.c
index cb9951d6036fb..d4de88bbbfbad 100644
--- a/drivers/net/ethernet/broadcom/genet/bcmgenet.c
+++ b/drivers/net/ethernet/broadcom/genet/bcmgenet.c
@@ -931,10 +931,13 @@ static int bcmgenet_set_coalesce(struct net_device *dev,
 	/* Program all TX queues with the same values, as there is no
 	 * ethtool knob to do coalescing on a per-queue basis
 	 */
-	for (i = 0; i <= priv->hw_params->tx_queues; i++)
+	for (i = 0; i <= priv->hw_params->tx_queues; i++) {
+		priv->tx_rings[i].tx_max_coalesced_frames =
+			ec->tx_max_coalesced_frames;
 		bcmgenet_tdma_ring_writel(priv, i,
 					  ec->tx_max_coalesced_frames,
 					  DMA_MBUF_DONE_THRESH);
+	}
 
 	for (i = 0; i <= priv->hw_params->rx_queues; i++)
 		bcmgenet_set_ring_rx_coalesce(&priv->rx_rings[i], ec);
@@ -2748,7 +2751,8 @@ static void bcmgenet_init_tx_ring(struct bcmgenet_priv *priv,
 
 	bcmgenet_tdma_ring_writel(priv, index, 0, TDMA_PROD_INDEX);
 	bcmgenet_tdma_ring_writel(priv, index, 0, TDMA_CONS_INDEX);
-	bcmgenet_tdma_ring_writel(priv, index, 1, DMA_MBUF_DONE_THRESH);
+	bcmgenet_tdma_ring_writel(priv, index, ring->tx_max_coalesced_frames,
+				  DMA_MBUF_DONE_THRESH);
 	/* Disable rate control for now */
 	bcmgenet_tdma_ring_writel(priv, index, flow_period_val,
 				  TDMA_FLOW_PERIOD);
@@ -4166,6 +4170,8 @@ static int bcmgenet_probe(struct platform_device *pdev)
 		priv->rx_rings[i].index = i;
 		priv->rx_rings[i].rx_max_coalesced_frames = 1;
 	}
+	for (i = 0; i <= priv->hw_params->tx_queues; i++)
+		priv->tx_rings[i].tx_max_coalesced_frames = 1;
 
 	/* Initialize u64 stats seq counter for 32bit machines */
 	for (i = 0; i <= GENET_MAX_MQ_CNT; i++) {
diff --git a/drivers/net/ethernet/broadcom/genet/bcmgenet.h b/drivers/net/ethernet/broadcom/genet/bcmgenet.h
index 86f2aed20dbe8..e48ce39d3e7c8 100644
--- a/drivers/net/ethernet/broadcom/genet/bcmgenet.h
+++ b/drivers/net/ethernet/broadcom/genet/bcmgenet.h
@@ -553,6 +553,7 @@ struct bcmgenet_tx_ring {
 	unsigned int	prod_index;	/* Tx ring producer index SW copy */
 	unsigned int	cb_ptr;		/* Tx ring initial CB ptr */
 	unsigned int	end_ptr;	/* Tx ring end CB ptr */
+	unsigned int	tx_max_coalesced_frames;
 	struct bcmgenet_priv *priv;
 };
 

-- 
2.53.0