Re: [PATCH net-next v3 2/2] net: phy: aquantia: allow forcing order of MDI pairs

[Jon Hunter]

On 11/10/2024 18:37, Jon Hunter wrote:
> Hi Daniel,
>
> On 04/10/2024 17:18, Daniel Golle wrote:
> > Despite supporting Auto MDI-X, it looks like Aquantia only supports
> > swapping pair (1,2) with pair (3,6) like it used to be for MDI-X on
> > 100MBit/s networks.
> >
> > When all 4 pairs are in use (for 1000MBit/s or faster) the link does not
> > come up with pair order is not configured correctly, either using
> > MDI_CFG pin or using the "PMA Receive Reserved Vendor Provisioning 1"
> > register.
> >
> > Normally, the order of MDI pairs being either ABCD or DCBA is configured
> > by pulling the MDI_CFG pin.
> >
> > However, some hardware designs require overriding the value configured
> > by that bootstrap pin. The PHY allows doing that by setting a bit in
> > "PMA Receive Reserved Vendor Provisioning 1" register which allows
> > ignoring the state of the MDI_CFG pin and another bit configuring
> > whether the order of MDI pairs should be normal (ABCD) or reverse
> > (DCBA). Pair polarity is not affected and remains identical in both
> > settings.
> >
> > Introduce property "marvell,mdi-cfg-order" which allows forcing either
> > normal or reverse order of the MDI pairs from DT.
> >
> > If the property isn't present, the behavior is unchanged and MDI pair
> > order configuration is untouched (ie. either the result of MDI_CFG pin
> > pull-up/pull-down, or pair order override already configured by the
> > bootloader before Linux is started).
> >
> > Forcing normal pair order is required on the Adtran SDG-8733A Wi-Fi 7
> > residential gateway.
> >
> > Signed-off-by: Daniel Golle <daniel@xxxxxxxxxxxxxx>
> > ---
> > v3: use u32 'marvell,mdi-cfg-order' instead of two mutually exclusive
> >      properties as suggested
> > v2: add missing 'static' keyword, improve commit description
> >
> >   drivers/net/phy/aquantia/aquantia_main.c | 33 ++++++++++++++++++++++++
> >   1 file changed, 33 insertions(+)
> >
> > diff --git a/drivers/net/phy/aquantia/aquantia_main.c 
> > b/drivers/net/phy/aquantia/aquantia_main.c
> > index 4d156d406bab..dcad3fa1ddc3 100644
> > --- a/drivers/net/phy/aquantia/aquantia_main.c
> > +++ b/drivers/net/phy/aquantia/aquantia_main.c
> > @@ -11,6 +11,7 @@
> >   #include <linux/module.h>
> >   #include <linux/delay.h>
> >   #include <linux/bitfield.h>
> > +#include <linux/of.h>
> >   #include <linux/phy.h>
> >   #include "aquantia.h"
> > @@ -71,6 +72,11 @@
> >   #define MDIO_AN_TX_VEND_INT_MASK2        0xd401
> >   #define MDIO_AN_TX_VEND_INT_MASK2_LINK        BIT(0)
> > +#define PMAPMD_RSVD_VEND_PROV            0xe400
> > +#define PMAPMD_RSVD_VEND_PROV_MDI_CONF        GENMASK(1, 0)
> > +#define PMAPMD_RSVD_VEND_PROV_MDI_REVERSE    BIT(0)
> > +#define PMAPMD_RSVD_VEND_PROV_MDI_FORCE        BIT(1)
> > +
> >   #define MDIO_AN_RX_LP_STAT1            0xe820
> >   #define MDIO_AN_RX_LP_STAT1_1000BASET_FULL    BIT(15)
> >   #define MDIO_AN_RX_LP_STAT1_1000BASET_HALF    BIT(14)
> > @@ -485,6 +491,29 @@ static void aqr107_chip_info(struct phy_device 
> > *phydev)
> >              fw_major, fw_minor, build_id, prov_id);
> >   }
> > +static int aqr107_config_mdi(struct phy_device *phydev)
> > +{
> > +    struct device_node *np = phydev->mdio.dev.of_node;
> > +    u32 mdi_conf;
> > +    int ret;
> > +
> > +    ret = of_property_read_u32(np, "marvell,mdi-cfg-order", &mdi_conf);
> > +
> > +    /* Do nothing in case property "marvell,mdi-cfg-order" is not 
> > present */
> > +    if (ret == -ENOENT)
> > +        return 0;
>
>
> This change is breaking networking for one of our Tegra boards and on 
> boot I am seeing ...
>
>   tegra-mgbe 6800000.ethernet eth0: Register MEM_TYPE_PAGE_POOL RxQ-0
>   tegra-mgbe 6800000.ethernet eth0: __stmmac_open: Cannot attach to PHY
>   (error: -22)
>
> The issue is that of_property_read_u32() does not return -ENOENT if the 
> property is missing, it actually returns -EINVAL. See the description of 
> of_property_read_variable_u32_array() which is called by 
> of_property_read_u32().
>
> Andrew, can we drop this change from -next until this is fixed?

Sorry, I believe Jakub applied and not Andrew.

Jon

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