diff mbox series

[net-next,v4,5/7] net: stmmac: Signal to PHY/PCS drivers to keep RX clock on

Message ID 20240221-rxc_bugfix-v4-5-4883ee1cc7b1@bootlin.com (mailing list archive)
State Superseded
Delegated to: Geert Uytterhoeven
Headers show
Series Fix missing PHY-to-MAC RX clock | expand

Commit Message

Romain Gantois Feb. 21, 2024, 1:04 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

Jakub Kicinski Feb. 21, 2024, 7:14 p.m. UTC | #1
On Wed, 21 Feb 2024 14:04:22 +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>

breaks allmodconfig:

ERROR: modpost: "phylink_pcs_pre_init" [drivers/net/ethernet/stmicro/stmmac/stmmac.ko] undefined!
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 ec4f6377b5ee..caf71a502ff2 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 =
@@ -3407,6 +3410,10 @@  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) {