[PATCH net] net: stmmac: Set MAC's flow control register to reflect current settings

[PATCH net] net: stmmac: Set MAC's flow control register to reflect current settings

[Goh, Wei Sheng]

Currently, pause frame register GMAC_RX_FLOW_CTRL_RFE is not updated
correctly when 'ethtool -A <IFACE> autoneg off rx off tx off' command
is issued. This fix ensures the flow control change is reflected directly
in the GMAC_RX_FLOW_CTRL_RFE register.

Fixes: 46f69ded988d ("net: stmmac: Use resolved link config in mac_link_up()")
Cc: <stable@vger.kernel.org> # 5.10.x
Signed-off-by: Goh, Wei Sheng <wei.sheng.goh@intel.com>
Signed-off-by: Noor Azura Ahmad Tarmizi <noor.azura.ahmad.tarmizi@intel.com>
---
 drivers/net/ethernet/stmicro/stmmac/dwmac4_core.c |  3 +++
 drivers/net/ethernet/stmicro/stmmac/stmmac_main.c | 12 ++++++++++--
 2 files changed, 13 insertions(+), 2 deletions(-)

diff --git a/drivers/net/ethernet/stmicro/stmmac/dwmac4_core.c b/drivers/net/ethernet/stmicro/stmmac/dwmac4_core.c
index c25bfecb4a2d..369db308b1dd 100644
--- a/drivers/net/ethernet/stmicro/stmmac/dwmac4_core.c
+++ b/drivers/net/ethernet/stmicro/stmmac/dwmac4_core.c
@@ -748,6 +748,9 @@ static void dwmac4_flow_ctrl(struct mac_device_info *hw, unsigned int duplex,
 	if (fc & FLOW_RX) {
 		pr_debug("\tReceive Flow-Control ON\n");
 		flow |= GMAC_RX_FLOW_CTRL_RFE;
+	} else {
+		pr_debug("\tReceive Flow-Control OFF\n");
+		flow &= ~GMAC_RX_FLOW_CTRL_RFE;
 	}
 	writel(flow, ioaddr + GMAC_RX_FLOW_CTRL);
 
diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
index 8273e6a175c8..ab7f48f32f5b 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
@@ -1061,8 +1061,16 @@ static void stmmac_mac_link_up(struct phylink_config *config,
 		ctrl |= priv->hw->link.duplex;
 
 	/* Flow Control operation */
-	if (tx_pause && rx_pause)
-		stmmac_mac_flow_ctrl(priv, duplex);
+	if (rx_pause && tx_pause)
+		priv->flow_ctrl = FLOW_AUTO;
+	else if (rx_pause && !tx_pause)
+		priv->flow_ctrl = FLOW_RX;
+	else if (!rx_pause && tx_pause)
+		priv->flow_ctrl = FLOW_TX;
+	else if (!rx_pause && !tx_pause)
+		priv->flow_ctrl = FLOW_OFF;
+
+	stmmac_mac_flow_ctrl(priv, duplex);
 
 	if (ctrl != old_ctrl)
 		writel(ctrl, priv->ioaddr + MAC_CTRL_REG);
-- 
2.17.1

Re: [PATCH net] net: stmmac: Set MAC's flow control register to reflect current settings

[Russell King (Oracle)]

On Fri, Nov 18, 2022 at 03:20:51PM +0800, Goh, Wei Sheng wrote:
> diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
> index 8273e6a175c8..ab7f48f32f5b 100644
> --- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
> +++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
> @@ -1061,8 +1061,16 @@ static void stmmac_mac_link_up(struct phylink_config *config,
>  		ctrl |= priv->hw->link.duplex;
>  
>  	/* Flow Control operation */
> -	if (tx_pause && rx_pause)
> -		stmmac_mac_flow_ctrl(priv, duplex);
> +	if (rx_pause && tx_pause)
> +		priv->flow_ctrl = FLOW_AUTO;
> +	else if (rx_pause && !tx_pause)
> +		priv->flow_ctrl = FLOW_RX;
> +	else if (!rx_pause && tx_pause)
> +		priv->flow_ctrl = FLOW_TX;
> +	else if (!rx_pause && !tx_pause)
> +		priv->flow_ctrl = FLOW_OFF;

Since "if (!rx_pause && !tx_pause)" will always be true at this point,
you can eliminate this needless last condition, which will make the code
a little more readable.

Thanks.

-- 
RMK's Patch system: https://www.armlinux.org.uk/developer/patches/
FTTP is here! 40Mbps down 10Mbps up. Decent connectivity at last!