* [PATCH net] net: phylink: treat PSGMII as an inband capable interface
@ 2026-08-07 19:49 Sandeep Sondagar
2026-08-07 20:16 ` Andrew Lunn
` (3 more replies)
0 siblings, 4 replies; 6+ 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] 6+ messages in thread
* Re: [PATCH net] net: phylink: treat PSGMII as an inband capable interface
2026-08-07 19:49 [PATCH net] net: phylink: treat PSGMII as an inband capable interface Sandeep Sondagar
@ 2026-08-07 20:16 ` Andrew Lunn
2026-08-08 1:56 ` [PATCH net v2] " Sandeep Sondagar
` (2 subsequent siblings)
3 siblings, 0 replies; 6+ messages in thread
From: Andrew Lunn @ 2026-08-07 20:16 UTC (permalink / raw)
To: Sandeep Sondagar
Cc: netdev, linux, hkallweit1, davem, edumazet, kuba, pabeni,
linux-kernel
On Sat, Aug 08, 2026 at 01:19:37AM +0530, Sandeep Sondagar wrote:
> 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>
If you are targeting net, this needs a Fixes: tag. When did this
break?
Andrew
^ permalink raw reply [flat|nested] 6+ messages in thread
* [PATCH net v2] net: phylink: treat PSGMII as an inband capable interface
2026-08-07 19:49 [PATCH net] net: phylink: treat PSGMII as an inband capable interface Sandeep Sondagar
2026-08-07 20:16 ` Andrew Lunn
@ 2026-08-08 1:56 ` Sandeep Sondagar
2026-08-08 2:09 ` Sandeep Sondagar
2026-08-08 2:11 ` Sandeep Sondagar
3 siblings, 0 replies; 6+ messages in thread
From: Sandeep Sondagar @ 2026-08-08 1:56 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 in-band 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 in-band and the resolved link speed comes from the PHY
in-band word.
Fixes: 83b5f0253b1e ("net: phy: Introduce PSGMII PHY interface mode")
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] 6+ messages in thread
* [PATCH net v2] net: phylink: treat PSGMII as an inband capable interface
2026-08-07 19:49 [PATCH net] net: phylink: treat PSGMII as an inband capable interface Sandeep Sondagar
2026-08-07 20:16 ` Andrew Lunn
2026-08-08 1:56 ` [PATCH net v2] " Sandeep Sondagar
@ 2026-08-08 2:09 ` Sandeep Sondagar
2026-08-08 2:11 ` Sandeep Sondagar
3 siblings, 0 replies; 6+ messages in thread
From: Sandeep Sondagar @ 2026-08-08 2:09 UTC (permalink / raw)
To: netdev
Cc: linux, andrew, hkallweit1, davem, edumazet, kuba, pabeni,
linux-kernel, j4g8y7, robert.marko, Sandeep Sondagar
PSGMII (the Qualcomm 5-port SGMII) conveys the link negotiation result
from the PHY back to the MAC through per-channel in-band 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 in-band and the resolved link speed comes from the PHY
in-band word.
Fixes: 83b5f0253b1e ("net: phy: Introduce PSGMII PHY interface mode")
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] 6+ messages in thread
* [PATCH net v2] net: phylink: treat PSGMII as an inband capable interface
[not found] <20260712194937.785825-1-sandeepsondagar@gmail.com>
@ 2026-08-08 2:09 ` Sandeep Sondagar
0 siblings, 0 replies; 6+ messages in thread
From: Sandeep Sondagar @ 2026-08-08 2:09 UTC (permalink / raw)
To: netdev
Cc: linux, andrew, hkallweit1, davem, edumazet, kuba, pabeni,
linux-kernel, j4g8y7, robert.marko, Sandeep Sondagar
PSGMII (the Qualcomm 5-port SGMII) conveys the link negotiation result
from the PHY back to the MAC through per-channel in-band 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 in-band and the resolved link speed comes from the PHY
in-band word.
Fixes: 83b5f0253b1e ("net: phy: Introduce PSGMII PHY interface mode")
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] 6+ messages in thread
* [PATCH net v2] net: phylink: treat PSGMII as an inband capable interface
2026-08-07 19:49 [PATCH net] net: phylink: treat PSGMII as an inband capable interface Sandeep Sondagar
` (2 preceding siblings ...)
2026-08-08 2:09 ` Sandeep Sondagar
@ 2026-08-08 2:11 ` Sandeep Sondagar
3 siblings, 0 replies; 6+ messages in thread
From: Sandeep Sondagar @ 2026-08-08 2:11 UTC (permalink / raw)
To: netdev
Cc: linux, andrew, hkallweit1, davem, edumazet, kuba, pabeni,
linux-kernel, j4g8y7, robert.marko, Sandeep Sondagar
PSGMII (the Qualcomm 5-port SGMII) conveys the link negotiation result
from the PHY back to the MAC through per-channel in-band 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 in-band and the resolved link speed comes from the PHY
in-band word.
Fixes: 83b5f0253b1e ("net: phy: Introduce PSGMII PHY interface mode")
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] 6+ messages in thread
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Thread overview: 6+ messages (download: mbox.gz follow: Atom feed
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2026-08-07 19:49 [PATCH net] net: phylink: treat PSGMII as an inband capable interface Sandeep Sondagar
2026-08-07 20:16 ` Andrew Lunn
2026-08-08 1:56 ` [PATCH net v2] " Sandeep Sondagar
2026-08-08 2:09 ` Sandeep Sondagar
2026-08-08 2:11 ` Sandeep Sondagar
[not found] <20260712194937.785825-1-sandeepsondagar@gmail.com>
2026-08-08 2:09 ` Sandeep Sondagar
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