diff mbox series

[RFC,net-next,18/19] net: mvpp2: add ring size validation before enabling FC

Message ID 1610292623-15564-19-git-send-email-stefanc@marvell.com (mailing list archive)
State RFC
Delegated to: Netdev Maintainers
Headers show
Series net: mvpp2: Add TX Flow Control support | expand

Checks

Context Check Description
netdev/cover_letter success Link
netdev/fixes_present success Link
netdev/patch_count fail Series longer than 15 patches
netdev/tree_selection success Clearly marked for net-next
netdev/subject_prefix success Link
netdev/cc_maintainers success CCed 5 of 5 maintainers
netdev/source_inline success Was 0 now: 0
netdev/verify_signedoff success Link
netdev/module_param success Was 0 now: 0
netdev/build_32bit success Errors and warnings before: 13 this patch: 13
netdev/kdoc success Errors and warnings before: 0 this patch: 0
netdev/verify_fixes success Link
netdev/checkpatch success total: 0 errors, 0 warnings, 0 checks, 28 lines checked
netdev/build_allmodconfig_warn success Errors and warnings before: 13 this patch: 13
netdev/header_inline success Link
netdev/stable success Stable not CCed

Commit Message

Stefan Chulski Jan. 10, 2021, 3:30 p.m. UTC 
From: Stefan Chulski <stefanc@marvell.com>

This patch add ring size validation before enabling FC.
1. Flow control cannot be enabled if ring size is below start
threshold.
2. Flow control disabled if ring size set below start
threshold.

Signed-off-by: Stefan Chulski <stefanc@marvell.com>
---
 drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c | 16 ++++++++++++++++
 1 file changed, 16 insertions(+)

Comments

Andrew Lunn Jan. 10, 2021, 5:37 p.m. UTC | #1 
On Sun, Jan 10, 2021 at 05:30:22PM +0200, stefanc@marvell.com wrote:
> From: Stefan Chulski <stefanc@marvell.com>
> 
> This patch add ring size validation before enabling FC.
> 1. Flow control cannot be enabled if ring size is below start
> threshold.
> 2. Flow control disabled if ring size set below start
> threshold.

You should also tell phylink if pause is not supported, so it can
change what is auto-negotiated, letting the link partner know.

       Andrew
diff mbox series

Patch

diff --git a/drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c b/drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c
index 06e1000..3607382 100644
--- a/drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c
+++ b/drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c
@@ -5372,6 +5372,15 @@  static int mvpp2_ethtool_set_ringparam(struct net_device *dev,
 	if (err)
 		return err;
 
+	if (ring->rx_pending < MSS_THRESHOLD_START && port->tx_fc) {
+		netdev_warn(dev, "TX FC disabled. Ring size is less than %d\n",
+			    MSS_THRESHOLD_START);
+		port->tx_fc = false;
+		mvpp2_rxq_disable_fc(port);
+		if (port->priv->hw_version == MVPP23)
+			mvpp23_rx_fifo_fc_en(port->priv, port->id, false);
+	}
+
 	if (!netif_running(dev)) {
 		port->rx_ring_size = ring->rx_pending;
 		port->tx_ring_size = ring->tx_pending;
@@ -5439,6 +5448,13 @@  static int mvpp2_ethtool_set_pause_param(struct net_device *dev,
 
 	if (pause->tx_pause && port->priv->global_tx_fc &&
 	    bm_underrun_protect) {
+		if (port->rx_ring_size < MSS_THRESHOLD_START) {
+			netdev_err(dev, "TX FC cannot be supported.");
+			netdev_err(dev, "Ring size is less than %d\n",
+				   MSS_THRESHOLD_START);
+			return -EINVAL;
+		}
+
 		port->tx_fc = true;
 		mvpp2_rxq_enable_fc(port);
 		if (port->priv->percpu_pools) {