diff options
| author | Prashanth Kumar KR <PrashanthKumar.K.R@amd.com> | 2026-07-09 15:20:06 +0530 |
|---|---|---|
| committer | Jakub Kicinski <kuba@kernel.org> | 2026-07-21 09:12:36 -0700 |
| commit | 4bf22afe53a1de4b44b04cf677fd5199089cbdff (patch) | |
| tree | fa3b07dad1928ccbbf973bcc73a4eb16be00f67b | |
| parent | e751256486d0ded20f5a9f9863467f1dce65142f (diff) | |
amd-xgbe: fix MAC_AUTO_SW handling in CL37 AN
MAC_AUTO_SW (VR_MII_DIG_CTRL1 bit 9) enables automatic XPCS speed
mode switching after CL37 auto-negotiation and is only meaningful in
SGMII MAC mode. The original code unconditionally set this bit on
every call to xgbe_an37_set(), including when called from
xgbe_an37_disable() with enable=false. This left MAC_AUTO_SW=1 after
AN was disabled, causing the XPCS to autonomously switch speed from
stale AN state during subsequent mode changes, breaking SGMII speed
negotiation on 1G copper SFP modules.
Patrick: This was breaking negotiation for all 1G SFP modules,
not just copper modules.
Fixes: 42fd432fe6d3 ("amd-xgbe: align CL37 AN sequence as per databook")
Reported-by: Patrick Oppenlander <patrick.oppenlander@gmail.com>
Link: https://lore.kernel.org/netdev/CAEg67GmFS0Q4oSZkz8zWdOzckSth9_vBPiOy6a7-d697C2w2Xg@mail.gmail.com
Signed-off-by: Prashanth Kumar KR <PrashanthKumar.K.R@amd.com>
Tested-by: Patrick Oppenlander <patrick.oppenlander@gmail.com>
Link: https://patch.msgid.link/20260709095006.3683940-1-prashanthkumar.k.r@amd.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
| -rw-r--r-- | drivers/net/ethernet/amd/xgbe/xgbe-mdio.c | 11 |
1 files changed, 8 insertions, 3 deletions
diff --git a/drivers/net/ethernet/amd/xgbe/xgbe-mdio.c b/drivers/net/ethernet/amd/xgbe/xgbe-mdio.c index fa0df6181207..12770af031eb 100644 --- a/drivers/net/ethernet/amd/xgbe/xgbe-mdio.c +++ b/drivers/net/ethernet/amd/xgbe/xgbe-mdio.c @@ -267,9 +267,14 @@ static void xgbe_an37_set(struct xgbe_prv_data *pdata, bool enable, XMDIO_WRITE(pdata, MDIO_MMD_VEND2, MDIO_CTRL1, reg); - reg = XMDIO_READ(pdata, MDIO_MMD_VEND2, MDIO_PCS_DIG_CTRL); - reg |= XGBE_VEND2_MAC_AUTO_SW; - XMDIO_WRITE(pdata, MDIO_MMD_VEND2, MDIO_PCS_DIG_CTRL, reg); + if (pdata->an_mode == XGBE_AN_MODE_CL37_SGMII) { + reg = XMDIO_READ(pdata, MDIO_MMD_VEND2, MDIO_PCS_DIG_CTRL); + if (enable) + reg |= XGBE_VEND2_MAC_AUTO_SW; + else + reg &= ~XGBE_VEND2_MAC_AUTO_SW; + XMDIO_WRITE(pdata, MDIO_MMD_VEND2, MDIO_PCS_DIG_CTRL, reg); + } } static void xgbe_an37_restart(struct xgbe_prv_data *pdata) |