On 11/04/2016 05:49 PM, Måns Rullgård wrote:
>>> But when doing so, both the Atheros 8035 and the Aurora NB8800 drivers
>>> will apply the delay.
>>>
>>> I think a better way of dealing with this is that both, PHY and MAC
>>> drivers exchange information so that the delay is applied only once.
>>
>> Exchange what information? The PHY device interface (phydev->interface)
>> conveys the needed information for both entities.
>
> There doesn't seem to be any consensus among the drivers regarding where
> the delay should be applied. Since only a few drivers, MAC or PHY, act
> on this property, most combinations still work by chance. It is common
> for boards to set the delay at the PHY using external config pins so no
> software setup is required (although I have one Sigma based board that
> gets this wrong). I suspect if drivers/net/ethernet/broadcom/genet were
> used with one of the four PHY drivers that also set the delay based on
> this DT property, things would go wrong.
>
Exactly, what about a patch like (I can make a formal submission, even
merge it with the patch discussed in this thread, consider this a RFC):
diff --git a/drivers/net/ethernet/aurora/nb8800.c
b/drivers/net/ethernet/aurora/nb8800.c
index fba2699..4217ff4 100644
--- a/drivers/net/ethernet/aurora/nb8800.c
+++ b/drivers/net/ethernet/aurora/nb8800.c
@@ -1283,6 +1283,10 @@ static int nb8800_tangox_init(struct net_device *dev)
case PHY_INTERFACE_MODE_RGMII_RXID:
case PHY_INTERFACE_MODE_RGMII_TXID:
pad_mode = PAD_MODE_RGMII;
+
+ if ((dev->phydev->flags & PHY_SUPPORTS_TXID) == 0)
+ pad_mode |= PAD_MODE_GTX_CLK_DELAY;
+
break;
default:
diff --git a/drivers/net/phy/at803x.c b/drivers/net/phy/at803x.c
index 2e0c759..5eddb04 100644
--- a/drivers/net/phy/at803x.c
+++ b/drivers/net/phy/at803x.c
@@ -426,7 +426,9 @@ static int at803x_aneg_done(struct phy_device *phydev)
.suspend = at803x_suspend,
.resume = at803x_resume,
.features = PHY_GBIT_FEATURES,
- .flags = PHY_HAS_INTERRUPT,
+ .flags = PHY_HAS_INTERRUPT |
+ PHY_SUPPORTS_RXID |
+ PHY_SUPPORTS_TXID,
.config_aneg = genphy_config_aneg,
.read_status = genphy_read_status,
.ack_interrupt = at803x_ack_interrupt,
diff --git a/include/linux/phy.h b/include/linux/phy.h
index e7e1fd3..0f0b17e 100644
--- a/include/linux/phy.h
+++ b/include/linux/phy.h
@@ -61,6 +61,8 @@
#define PHY_HAS_INTERRUPT 0x00000001
#define PHY_HAS_MAGICANEG 0x00000002
#define PHY_IS_INTERNAL 0x00000004
+#define PHY_SUPPORTS_RXID 0x00000008
+#define PHY_SUPPORTS_TXID 0x00000010
#define MDIO_DEVICE_IS_PHY 0x80000000
/* Interface Mode definitions */
