diff mbox series

[net-next,v16,4/7] net: stmmac: qcom-ethqos: update phy_mode to the resolved interface in mac_finish()

Message ID 20261014-qcom-sa8255p-emac-v16-4-0266c2ead980@oss.qualcomm.com (mailing list archive)
State New
Headers
Series net: stmmac: qcom-ethqos: add support for SCMI power domains |

Commit Message

Bartosz Golaszewski Oct. 14, 2026, 12:36 p.m. UTC 
ethqos->phy_mode is read by serdes_powerup() and
qcom_ethqos_set_sgmii_loopback() to configure the SerDes and its
wrapper for the correct interface. It is set once at probe from the DT
phy-mode property and never updated.

phylink resolves the actual runtime interface and passes it to the
mac_finish() callback. On platforms that only ever operate at one speed
these two values are always the same, but when the interface changes
at runtime - for example switching between SGMII and 2500BASE-X - the
stored value becomes stale. The next serdes_powerup() call, on
a subsequent link cycle, then reinitializes the SerDes to the wrong mode.

Update ethqos->phy_mode from the interface argument in
ethqos_mac_finish_serdes() so that it always reflects the last
resolved interface.

With that, we now update the phy_mode to the runtime-resolved interface,
so any subsequent resume with a 1G SGMII link skips the loopback setup
and the DMA reset hangs. To remedy this, extend the guard to include
PHY_INTERFACE_MODE_SGMII.

Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@oss.qualcomm.com>
---
 drivers/net/ethernet/stmicro/stmmac/dwmac-qcom-ethqos.c | 9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

Comments

Mohd Ayaan Anwar Oct. 17, 2026, 4:39 p.m. UTC | #1 
On Wed, Oct 14, 2026 at 02:36:43PM +0200, Bartosz Golaszewski wrote:
> ethqos->phy_mode is read by serdes_powerup() and
> qcom_ethqos_set_sgmii_loopback() to configure the SerDes and its
> wrapper for the correct interface. It is set once at probe from the DT
> phy-mode property and never updated.
> 
> phylink resolves the actual runtime interface and passes it to the
> mac_finish() callback. On platforms that only ever operate at one speed
> these two values are always the same, but when the interface changes
> at runtime - for example switching between SGMII and 2500BASE-X - the
> stored value becomes stale. The next serdes_powerup() call, on
> a subsequent link cycle, then reinitializes the SerDes to the wrong mode.
> 
> Update ethqos->phy_mode from the interface argument in
> ethqos_mac_finish_serdes() so that it always reflects the last
> resolved interface.
> 
> With that, we now update the phy_mode to the runtime-resolved interface,
> so any subsequent resume with a 1G SGMII link skips the loopback setup
> and the DMA reset hangs. To remedy this, extend the guard to include
> PHY_INTERFACE_MODE_SGMII.
> 
> Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@oss.qualcomm.com>
> ---

I am not sure but should this have a Fixes: tag?

Reviewed-by: Mohd Ayaan Anwar <mohd.anwar@oss.qualcomm.com>

	Ayaan
diff mbox series

Patch

diff --git a/drivers/net/ethernet/stmicro/stmmac/dwmac-qcom-ethqos.c b/drivers/net/ethernet/stmicro/stmmac/dwmac-qcom-ethqos.c
index e2e611a4d2c06bd567e9d5e353b3a4893623de6c..f7cc46d86591a220a183529a8f89456f9153385d 100644
--- a/drivers/net/ethernet/stmicro/stmmac/dwmac-qcom-ethqos.c
+++ b/drivers/net/ethernet/stmicro/stmmac/dwmac-qcom-ethqos.c
@@ -190,7 +190,8 @@  static void
 qcom_ethqos_set_sgmii_loopback(struct qcom_ethqos *ethqos, bool enable)
 {
 	if (!ethqos->needs_sgmii_loopback ||
-	    ethqos->phy_mode != PHY_INTERFACE_MODE_2500BASEX)
+	    (ethqos->phy_mode != PHY_INTERFACE_MODE_2500BASEX &&
+	     ethqos->phy_mode != PHY_INTERFACE_MODE_SGMII))
 		return;
 
 	rgmii_updatel(ethqos,
@@ -637,6 +638,12 @@  static int ethqos_mac_finish_serdes(struct net_device *ndev, void *priv,
 
 	qcom_ethqos_set_sgmii_loopback(ethqos, false);
 
+	/* The interface mode is only known once phylink has resolved it and
+	 * may change at runtime, so keep it in sync for later
+	 * serdes_powerup() and qcom_ethqos_set_sgmii_loopback() calls.
+	 */
+	ethqos->phy_mode = interface;
+
 	if (interface == PHY_INTERFACE_MODE_SGMII ||
 	    interface == PHY_INTERFACE_MODE_2500BASEX)
 		ret = phy_set_mode_ext(ethqos->serdes_phy, PHY_MODE_ETHERNET,