Re: [PATCH net-next] net: macb: set default_an_inband to true for SGMII
From: Conor Dooley <conor@kernel.org>
Date: 2026-03-12 15:01:43
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On Thu, Mar 12, 2026 at 06:38:55AM -0700, Charles Perry wrote:
Most platforms using GEM in SGMII mode use in-band autonegotiation
because it is on by default in GEM's 1G PCS and is always on since
commit e276e5e40e92 ("net: macb: Disable PCS auto-negotiation for SGMII
fixed-link mode"). Leave it on if possible using the "default_an_inband"
flag of "struct phylink_config" so that platforms that lack in-band
autonegotiation configurability at the PHY do not break with commit
1338cfef1ff1 ("net: macb: fix SGMII with inband aneg disabled") which
will turn off in-band autoneg for non hot pluggable PHYs.
Once the majority of the PHY drivers that support SGMII have the
->config_inband() callback, this commit could be reverted so that non
hot pluggable PHY use outband negotiation with macb, like its the case
for other MACs.
Fixes: 1338cfef1ff1 ("net: macb: fix SGMII with inband aneg disabled")
Closes: https://lore.kernel.org/r/20260304-nebulizer-rounding-40fbc81a2ba1@spud (local)Reported-by: Conor Dooley <conor.dooley@microchip.com>
Tested-by: Conor Dooley <conor@kernel.org>
Just as an FYI, you shouldn't insert tags that "certify" the quality of your patch that you weren't explicitly given. Reported-by/Suggested-by you can conjure up yourself where appropriate, but Tested-by/Acked-by/Reviewed-by need more care. But of course, I did test it, and it restored functionality on both boards that I have here, so: Tested-by: Conor Dooley <conor.dooley@microchip.com> Cheers, Conor.
quoted hunk ↗ jump to hunk
Signed-off-by: Charles Perry <charles.perry@microchip.com> --- drivers/net/ethernet/cadence/macb_main.c | 6 ++++++ 1 file changed, 6 insertions(+)diff --git a/drivers/net/ethernet/cadence/macb_main.c b/drivers/net/ethernet/cadence/macb_main.c index 963a5d4e1a88..d1fc6a9b9fe5 100644 --- a/drivers/net/ethernet/cadence/macb_main.c +++ b/drivers/net/ethernet/cadence/macb_main.c@@ -838,6 +838,12 @@ static int macb_mii_probe(struct net_device *dev) if (bp->phy_interface == PHY_INTERFACE_MODE_SGMII) { bp->phylink_config.poll_fixed_state = true; bp->phylink_config.get_fixed_state = macb_get_pcs_fixed_state; + /* The PCSAUTONEG bit in PCSCNTRL is on out of reset. Setting + * default_an_inband to true tells phylink to turn it off only + * if necessary (e.g. a fixed link or a PHY that doesn't support + * inband). + */ + bp->phylink_config.default_an_inband = true; } bp->phylink_config.mac_capabilities = MAC_ASYM_PAUSE |-- 2.47.3
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