[PATCH net-next] net: dsa: mv88e6xxx: Fix validation of built-in PHYs on 6095/6097

[PATCH net-next] net: dsa: mv88e6xxx: Fix validation of built-in PHYs on 6095/6097

[Tobias Waldekranz]

These chips have 8 built-in FE PHYs and 3 SERDES interfaces that can
run at 1G. With the blamed commit, the built-in PHYs could no longer
be connected to, using an MII PHY interface mode.

Create a separate .phylink_get_caps callback for these chips, which
takes the FE/GE split into consideration.

Fixes: 2ee84cfefb1e ("net: dsa: mv88e6xxx: convert to phylink_generic_validate()")
Signed-off-by: Tobias Waldekranz <tobias@waldekranz.com>
---
 drivers/net/dsa/mv88e6xxx/chip.c | 25 +++++++++++++++++++++++--
 1 file changed, 23 insertions(+), 2 deletions(-)

diff --git a/drivers/net/dsa/mv88e6xxx/chip.c b/drivers/net/dsa/mv88e6xxx/chip.c
index 85527fe4fcc8..622b3b4ed513 100644
--- a/drivers/net/dsa/mv88e6xxx/chip.c
+++ b/drivers/net/dsa/mv88e6xxx/chip.c
@@ -580,6 +580,27 @@ static const u8 mv88e6185_phy_interface_modes[] = {
 	[MV88E6185_PORT_STS_CMODE_PHY]		 = PHY_INTERFACE_MODE_SGMII,
 };
 
+static void mv88e6095_phylink_get_caps(struct mv88e6xxx_chip *chip, int port,
+				       struct phylink_config *config)
+{
+	u8 cmode = chip->ports[port].cmode;
+
+	config->mac_capabilities = MAC_SYM_PAUSE | MAC_10 | MAC_100;
+
+	if (mv88e6xxx_phy_is_internal(chip->ds, port)) {
+		if (cmode == MV88E6185_PORT_STS_CMODE_PHY)
+			__set_bit(PHY_INTERFACE_MODE_MII,
+				  config->supported_interfaces);
+	} else {
+		if (cmode < ARRAY_SIZE(mv88e6185_phy_interface_modes) &&
+		    mv88e6185_phy_interface_modes[cmode])
+			__set_bit(mv88e6185_phy_interface_modes[cmode],
+				  config->supported_interfaces);
+
+		config->mac_capabilities |= MAC_1000FD;
+	}
+}
+
 static void mv88e6185_phylink_get_caps(struct mv88e6xxx_chip *chip, int port,
 				       struct phylink_config *config)
 {
@@ -3803,7 +3824,7 @@ static const struct mv88e6xxx_ops mv88e6095_ops = {
 	.reset = mv88e6185_g1_reset,
 	.vtu_getnext = mv88e6185_g1_vtu_getnext,
 	.vtu_loadpurge = mv88e6185_g1_vtu_loadpurge,
-	.phylink_get_caps = mv88e6185_phylink_get_caps,
+	.phylink_get_caps = mv88e6095_phylink_get_caps,
 	.set_max_frame_size = mv88e6185_g1_set_max_frame_size,
 };
 
@@ -3850,7 +3871,7 @@ static const struct mv88e6xxx_ops mv88e6097_ops = {
 	.rmu_disable = mv88e6085_g1_rmu_disable,
 	.vtu_getnext = mv88e6352_g1_vtu_getnext,
 	.vtu_loadpurge = mv88e6352_g1_vtu_loadpurge,
-	.phylink_get_caps = mv88e6185_phylink_get_caps,
+	.phylink_get_caps = mv88e6095_phylink_get_caps,
 	.set_max_frame_size = mv88e6185_g1_set_max_frame_size,
 };
 
-- 
2.25.1

Re: [PATCH net-next] net: dsa: mv88e6xxx: Fix validation of built-in PHYs on 6095/6097

[Russell King (Oracle)]

Hi,

Thanks for spotting this. Some comments below.

On Sun, Feb 13, 2022 at 01:37:01AM +0100, Tobias Waldekranz wrote:
> +static void mv88e6095_phylink_get_caps(struct mv88e6xxx_chip *chip, int port,
> +				       struct phylink_config *config)
> +{
> +	u8 cmode = chip->ports[port].cmode;
> +
> +	config->mac_capabilities = MAC_SYM_PAUSE | MAC_10 | MAC_100;
> +
> +	if (mv88e6xxx_phy_is_internal(chip->ds, port)) {
> +		if (cmode == MV88E6185_PORT_STS_CMODE_PHY)
> +			__set_bit(PHY_INTERFACE_MODE_MII,
> +				  config->supported_interfaces);

Hmm. First, note that with mv88e6xxx_get_caps(), you'll end up with both
MII and GMII here. GMII is necessary as that's the phylib default if no
one specifies anything different in the firmware description. I assume
you've noticed a problem because you specify MII for the internal ports
in firmware?

I'm wondering what the point of checking the cmode here is - if the port
is internal, won't this switch always have cmode == PHY?

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Re: [PATCH net-next] net: dsa: mv88e6xxx: Fix validation of built-in PHYs on 6095/6097

[Tobias Waldekranz]

On Sun, Feb 13, 2022 at 12:58, "Russell King (Oracle)" <linux@armlinux.org.uk> wrote:
> Hi,
>
> Thanks for spotting this. Some comments below.
>
> On Sun, Feb 13, 2022 at 01:37:01AM +0100, Tobias Waldekranz wrote:
>> +static void mv88e6095_phylink_get_caps(struct mv88e6xxx_chip *chip, int port,
>> +				       struct phylink_config *config)
>> +{
>> +	u8 cmode = chip->ports[port].cmode;
>> +
>> +	config->mac_capabilities = MAC_SYM_PAUSE | MAC_10 | MAC_100;
>> +
>> +	if (mv88e6xxx_phy_is_internal(chip->ds, port)) {
>> +		if (cmode == MV88E6185_PORT_STS_CMODE_PHY)
>> +			__set_bit(PHY_INTERFACE_MODE_MII,
>> +				  config->supported_interfaces);
>
> Hmm. First, note that with mv88e6xxx_get_caps(), you'll end up with both
> MII and GMII here. GMII is necessary as that's the phylib default if no

I did notice that.

> one specifies anything different in the firmware description. I assume
> you've noticed a problem because you specify MII for the internal ports
> in firmware?

Precisely.

> I'm wondering what the point of checking the cmode here is - if the port
> is internal, won't this switch always have cmode == PHY?

For all intents and purposes: I think so. It is just that the functional
spec. also lists cmode == 4 == disabled (PHYDetect == 0) for the
internal ports. So I figured that there might be some way of strapping
ports as disabled that I had never come across.

Do you think we should drop it?

Re: [PATCH net-next] net: dsa: mv88e6xxx: Fix validation of built-in PHYs on 6095/6097

[Russell King (Oracle)]

On Sun, Feb 13, 2022 at 04:32:51PM +0100, Tobias Waldekranz wrote:
> On Sun, Feb 13, 2022 at 12:58, "Russell King (Oracle)" <linux@armlinux.org.uk> wrote:
> > I'm wondering what the point of checking the cmode here is - if the port
> > is internal, won't this switch always have cmode == PHY?
> 
> For all intents and purposes: I think so. It is just that the functional
> spec. also lists cmode == 4 == disabled (PHYDetect == 0) for the
> internal ports. So I figured that there might be some way of strapping
> ports as disabled that I had never come across.

I don't think there is a way to pinstrap the internal ports. As far as
I can see, the only way would be for software to program PHY Detect to
zero.

If we wanted a port to be disabled, then describing it in firmware as
being enabled would be a bug. If it isn't described in firmware, the
DSA code won't even consider looking at the port.

> Do you think we should drop it?

I think so.

Thanks.

-- 
RMK's Patch system: https://www.armlinux.org.uk/developer/patches/
FTTP is here! 40Mbps down 10Mbps up. Decent connectivity at last!