diff mbox series

[net-next,v5,5/7] net: stmmac: Signal to PHY/PCS drivers to keep RX clock on

Message ID 20240301-rxc_bugfix-v5-5-8dac30230050@bootlin.com (mailing list archive)
State New, archived
Headers show
Series Fix missing PHY-to-MAC RX clock | expand

Commit Message

Romain Gantois March 1, 2024, 3:35 p.m. UTC
There is a reocurring issue with stmmac controllers where the MAC fails to
initialize its hardware if an RX clock signal isn't provided on the MAC/PHY
link.

This causes issues when PHY or PCS devices either go into suspend while
cutting the RX clock or do not bring the clock signal up early enough for
the MAC to initialize successfully.

Set the mac_requires_rxc flag in the stmmac phylink config so that PHY/PCS
drivers know to keep the RX clock up at all times.

Reported-by: Clark Wang <xiaoning.wang@nxp.com>
Link: https://lore.kernel.org/all/20230202081559.3553637-1-xiaoning.wang@nxp.com/
Reported-by: Clément Léger <clement.leger@bootlin.com>
Link: https://lore.kernel.org/linux-arm-kernel/20230116103926.276869-4-clement.leger@bootlin.com/
Suggested-by: Russell King <linux@armlinux.org.uk>
Signed-off-by: Romain Gantois <romain.gantois@bootlin.com>
---
 drivers/net/ethernet/stmicro/stmmac/stmmac_main.c | 7 +++++++
 1 file changed, 7 insertions(+)

Comments

Andrew Lunn March 4, 2024, 1:43 p.m. UTC | #1
On Fri, Mar 01, 2024 at 04:35:02PM +0100, Romain Gantois wrote:
> There is a reocurring issue with stmmac controllers where the MAC fails to
> initialize its hardware if an RX clock signal isn't provided on the MAC/PHY
> link.
> 
> This causes issues when PHY or PCS devices either go into suspend while
> cutting the RX clock or do not bring the clock signal up early enough for
> the MAC to initialize successfully.
> 
> Set the mac_requires_rxc flag in the stmmac phylink config so that PHY/PCS
> drivers know to keep the RX clock up at all times.
> 
> Reported-by: Clark Wang <xiaoning.wang@nxp.com>
> Link: https://lore.kernel.org/all/20230202081559.3553637-1-xiaoning.wang@nxp.com/
> Reported-by: Clément Léger <clement.leger@bootlin.com>
> Link: https://lore.kernel.org/linux-arm-kernel/20230116103926.276869-4-clement.leger@bootlin.com/
> Suggested-by: Russell King <linux@armlinux.org.uk>
> Signed-off-by: Romain Gantois <romain.gantois@bootlin.com>

Reviewed-by: Andrew Lunn <andrew@lunn.ch>

    Andrew
Russell King (Oracle) March 4, 2024, 2:34 p.m. UTC | #2
On Fri, Mar 01, 2024 at 04:35:02PM +0100, Romain Gantois wrote:
> There is a reocurring issue with stmmac controllers where the MAC fails to
> initialize its hardware if an RX clock signal isn't provided on the MAC/PHY
> link.
> 
> This causes issues when PHY or PCS devices either go into suspend while
> cutting the RX clock or do not bring the clock signal up early enough for
> the MAC to initialize successfully.
> 
> Set the mac_requires_rxc flag in the stmmac phylink config so that PHY/PCS
> drivers know to keep the RX clock up at all times.
> 
> Reported-by: Clark Wang <xiaoning.wang@nxp.com>
> Link: https://lore.kernel.org/all/20230202081559.3553637-1-xiaoning.wang@nxp.com/
> Reported-by: Clément Léger <clement.leger@bootlin.com>
> Link: https://lore.kernel.org/linux-arm-kernel/20230116103926.276869-4-clement.leger@bootlin.com/
> Suggested-by: Russell King <linux@armlinux.org.uk>

This should be:
Co-developed-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>

> Signed-off-by: Romain Gantois <romain.gantois@bootlin.com>
> ---
>  drivers/net/ethernet/stmicro/stmmac/stmmac_main.c | 7 +++++++
>  1 file changed, 7 insertions(+)
> 
> diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
> index 79844dbe4258..2290f4808d7e 100644
> --- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
> +++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
> @@ -1218,6 +1218,9 @@ static int stmmac_phy_setup(struct stmmac_priv *priv)
>  	priv->phylink_config.type = PHYLINK_NETDEV;
>  	priv->phylink_config.mac_managed_pm = true;
>  
> +	/* Stmmac always requires an RX clock for hardware initialization */
> +	priv->phylink_config.mac_requires_rxc = true;
> +
>  	mdio_bus_data = priv->plat->mdio_bus_data;
>  	if (mdio_bus_data)
>  		priv->phylink_config.ovr_an_inband =
> @@ -3408,6 +3411,10 @@ static int stmmac_hw_setup(struct net_device *dev, bool ptp_register)
>  	u32 chan;
>  	int ret;
>  
> +	/* Make sure RX clock is enabled */
> +	if (priv->hw->phylink_pcs)
> +		phylink_pcs_pre_init(priv->phylink, priv->hw->phylink_pcs);
> +
>  	/* DMA initialization and SW reset */
>  	ret = stmmac_init_dma_engine(priv);
>  	if (ret < 0) {
> 
> -- 
> 2.43.2
> 
>
diff mbox series

Patch

diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
index 79844dbe4258..2290f4808d7e 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
@@ -1218,6 +1218,9 @@  static int stmmac_phy_setup(struct stmmac_priv *priv)
 	priv->phylink_config.type = PHYLINK_NETDEV;
 	priv->phylink_config.mac_managed_pm = true;
 
+	/* Stmmac always requires an RX clock for hardware initialization */
+	priv->phylink_config.mac_requires_rxc = true;
+
 	mdio_bus_data = priv->plat->mdio_bus_data;
 	if (mdio_bus_data)
 		priv->phylink_config.ovr_an_inband =
@@ -3408,6 +3411,10 @@  static int stmmac_hw_setup(struct net_device *dev, bool ptp_register)
 	u32 chan;
 	int ret;
 
+	/* Make sure RX clock is enabled */
+	if (priv->hw->phylink_pcs)
+		phylink_pcs_pre_init(priv->phylink, priv->hw->phylink_pcs);
+
 	/* DMA initialization and SW reset */
 	ret = stmmac_init_dma_engine(priv);
 	if (ret < 0) {