Netdev List
 help / color / mirror / Atom feed
* [PATCH net] net: phylink: treat PSGMII as an inband capable interface
@ 2026-08-07 19:49 Sandeep Sondagar
  2026-08-08  1:56 ` [PATCH net v2] " Sandeep Sondagar
                   ` (2 more replies)
  0 siblings, 3 replies; 4+ messages in thread
From: Sandeep Sondagar @ 2026-08-07 19:49 UTC (permalink / raw)
  To: netdev
  Cc: linux, andrew, hkallweit1, davem, edumazet, kuba, pabeni,
	linux-kernel, Sandeep Sondagar

PSGMII (the Qualcomm 5-port SGMII) conveys the link negotiation result
from the PHY back to the MAC through per-channel inband SGMII words,
exactly like SGMII and QSGMII.

However, PHY_INTERFACE_MODE_PSGMII is missing from
phylink_get_inband_type(), so phylink reports INBAND_NONE for it and
phylink_pcs_neg_mode() falls back to PHYLINK_PCS_NEG_NONE. The PCS is
then programmed in force mode and its control-register speed bits (which
default to 1000base) are used, so a slower copper link - e.g. 100base-T
- is reported as 1Gbps and cannot pass traffic.

Classify PSGMII alongside SGMII and QSGMII as INBAND_CISCO_SGMII so the
PCS negotiates inband and the resolved link speed comes from the PHY
inband word.

Signed-off-by: Sandeep Sondagar <sandeepsondagar@gmail.com>
---
 drivers/net/phy/phylink.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/net/phy/phylink.c b/drivers/net/phy/phylink.c
index 18d2ead97aa5..983a1a3cee37 100644
--- a/drivers/net/phy/phylink.c
+++ b/drivers/net/phy/phylink.c
@@ -1040,6 +1040,7 @@ static enum inband_type phylink_get_inband_type(phy_interface_t interface)
 {
 	switch (interface) {
 	case PHY_INTERFACE_MODE_SGMII:
+	case PHY_INTERFACE_MODE_PSGMII:
 	case PHY_INTERFACE_MODE_QSGMII:
 	case PHY_INTERFACE_MODE_QUSGMII:
 	case PHY_INTERFACE_MODE_USXGMII:
-- 
2.43.0


^ permalink raw reply related	[flat|nested] 4+ messages in thread

end of thread, other threads:[~2026-08-08  2:11 UTC | newest]

Thread overview: 4+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
     [not found] <20260712194937.785825-1-sandeepsondagar@gmail.com>
2026-08-08  2:09 ` [PATCH net v2] net: phylink: treat PSGMII as an inband capable interface Sandeep Sondagar
2026-08-07 19:49 [PATCH net] " Sandeep Sondagar
2026-08-08  1:56 ` [PATCH net v2] " Sandeep Sondagar
2026-08-08  2:09 ` Sandeep Sondagar
2026-08-08  2:11 ` Sandeep Sondagar

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox