[PATCH v2 06/10] net: pcs: xpcs: add ANRESTART support for SGMII link recovery
COLD59d
REVIEWED: 1 (1M)
From: Coia Prant <hidden>
Date: 2026-08-01 14:24:11
Also in:
linux-arm-kernel, linux-devicetree, linux-phy, linux-renesas-soc, linux-rockchip, lkml
Subsystem:
ethernet phy library, networking drivers, synopsys designware ethernet xpcs driver, the rest · Maintainers:
Andrew Lunn, Heiner Kallweit, Andrew Lunn, "David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Linus Torvalds
Revision v2 of 2 in this series; 1 review trailer.
Revisions (2)
- rfc [diff vs current]
- v2 current
On some hardware using the DesignWare XPCS IP (e.g., RK3568 MAC side SGMII), the PCS does not automatically restart auto-negotiation when the link goes down and comes back up. Without an explicit ANRESTART, the link stays down forever. Add BMCR_ANRESTART in two places: 1. In xpcs_config_aneg_c37_sgmii(), when starting AN, set ANRESTART alongside ANENABLE to initiate a fresh negotiation. 2. In xpcs_get_state_c37_sgmii(), when link is down and AN completion is detected, clear the interrupt and trigger ANRESTART to restart the negotiation process. This change has been verified on: - RK3568 (Photonicat board) - Wangxun NICs (no regression) Tested-by: Jiawen Wu <jiawenwu@trustnetic.com> Signed-off-by: Coia Prant <redacted> --- drivers/net/pcs/pcs-xpcs.c | 17 +++++++++++++---- 1 file changed, 13 insertions(+), 4 deletions(-)
diff --git a/drivers/net/pcs/pcs-xpcs.c b/drivers/net/pcs/pcs-xpcs.c
index 0337e2bcc0125..28e98449e8ac2 100644
--- a/drivers/net/pcs/pcs-xpcs.c
+++ b/drivers/net/pcs/pcs-xpcs.c@@ -816,9 +816,14 @@ static int xpcs_config_aneg_c37_sgmii(struct dw_xpcs *xpcs, if (ret < 0) return ret; + /* Clear CL37 AN complete status */ + ret = xpcs_write(xpcs, MDIO_MMD_VEND2, DW_VR_MII_AN_INTR_STS, 0); + if (ret < 0) + return ret; + if (neg_mode == PHYLINK_PCS_NEG_INBAND_ENABLED) ret = xpcs_write(xpcs, MDIO_MMD_VEND2, MII_BMCR, - mdio_ctrl | BMCR_ANENABLE); + mdio_ctrl | BMCR_ANENABLE | BMCR_ANRESTART); return ret; }
@@ -1089,14 +1094,18 @@ static int xpcs_get_state_c37_sgmii(struct dw_xpcs *xpcs, state->duplex = DUPLEX_FULL; else state->duplex = DUPLEX_HALF; - return 0; } - /* Clear AN complete status or interrupt */ - if (state->an_complete) + if (state->an_complete) { + /* Clear AN complete status or interrupt */ xpcs_write(xpcs, MDIO_MMD_VEND2, DW_VR_MII_AN_INTR_STS, 0); + /* Initiate the next round of AN */ + xpcs_modify(xpcs, MDIO_MMD_VEND2, MII_BMCR, BMCR_ANRESTART, + BMCR_ANRESTART); + } + return 0; }
--
2.47.3