Starting with:
bcf3440c6dd7 ("net: phy: micrel: add phy-mode support for the KSZ9031 PHY")
the micrel phy driver started respecting phy-mode for the KSZ9031 PHY.
At least with kernel v5.8 configuration provided by this fixup was
overwritten by the micrel driver.
This fixup was providing following configuration:
RX path: 2.58ns delay
rx -0.42 (left shift) + rx_clk +0.96ns (right shift) =
1,38 + 1,2 internal RX delay = 2.58ns
TX path: 0.96ns delay
tx (no delay) + tx_clk 0.96ns (right shift) = 0.96ns
This configuration is outside of the recommended RGMII clock skew delays
and about in the middle of: rgmii-idrx and rgmii-id
Since most embedded systems do not have enough place to introduce
significant clock skew, rgmii-id is the way to go.
In case this patch breaks network functionality on your system, build
kernel with enabled MICREL_PHY. If it is still not working then try
following device tree options:
1. Set (or change) phy-mode in DT to:
phy-mode = "rgmii-id";
This actives internal delay for both RX and TX.
1. Set (or change) phy-mode in DT to:
phy-mode = "rgmii-idrx";
This actives internal delay for RX only.
3. Use following DT properties:
phy-mode = "rgmii";
txen-skew-psec = <0>;
rxdv-skew-psec = <0>;
rxd0-skew-psec = <0>;
rxd1-skew-psec = <0>;
rxd2-skew-psec = <0>;
rxd3-skew-psec = <0>;
rxc-skew-psec = <1860>;
txc-skew-psec = <1860>;
This activates the internal delays for RX and TX, with the value as
the fixup that is removed in this patch.
Signed-off-by: Oleksij Rempel <[email protected]>
---
arch/arm/mach-imx/mach-imx6q.c | 23 -----------------------
1 file changed, 23 deletions(-)
diff --git a/arch/arm/mach-imx/mach-imx6q.c b/arch/arm/mach-imx/mach-imx6q.c
index 703998ebb52e..78205f90da27 100644
--- a/arch/arm/mach-imx/mach-imx6q.c
+++ b/arch/arm/mach-imx/mach-imx6q.c
@@ -40,27 +40,6 @@ static int ksz9021rn_phy_fixup(struct phy_device *phydev)
return 0;
}
-static void mmd_write_reg(struct phy_device *dev, int device, int reg, int val)
-{
- phy_write(dev, 0x0d, device);
- phy_write(dev, 0x0e, reg);
- phy_write(dev, 0x0d, (1 << 14) | device);
- phy_write(dev, 0x0e, val);
-}
-
-static int ksz9031rn_phy_fixup(struct phy_device *dev)
-{
- /*
- * min rx data delay, max rx/tx clock delay,
- * min rx/tx control delay
- */
- mmd_write_reg(dev, 2, 4, 0);
- mmd_write_reg(dev, 2, 5, 0);
- mmd_write_reg(dev, 2, 8, 0x003ff);
-
- return 0;
-}
-
/*
* fixup for PLX PEX8909 bridge to configure GPIO1-7 as output High
* as they are used for slots1-7 PERST#
@@ -152,8 +131,6 @@ static void __init imx6q_enet_phy_init(void)
if (IS_BUILTIN(CONFIG_PHYLIB)) {
phy_register_fixup_for_uid(PHY_ID_KSZ9021, MICREL_PHY_ID_MASK,
ksz9021rn_phy_fixup);
- phy_register_fixup_for_uid(PHY_ID_KSZ9031, MICREL_PHY_ID_MASK,
- ksz9031rn_phy_fixup);
phy_register_fixup_for_uid(PHY_ID_AR8031, 0xffffffef,
ar8031_phy_fixup);
phy_register_fixup_for_uid(PHY_ID_AR8035, 0xffffffef,
--
2.29.2
On Tue, May 11, 2021 at 06:37:29AM +0200, Oleksij Rempel wrote:
> Starting with:
>
> bcf3440c6dd7 ("net: phy: micrel: add phy-mode support for the KSZ9031 PHY")
>
> the micrel phy driver started respecting phy-mode for the KSZ9031 PHY.
> At least with kernel v5.8 configuration provided by this fixup was
> overwritten by the micrel driver.
>
> This fixup was providing following configuration:
>
> RX path: 2.58ns delay
> rx -0.42 (left shift) + rx_clk +0.96ns (right shift) =
> 1,38 + 1,2 internal RX delay = 2.58ns
> TX path: 0.96ns delay
> tx (no delay) + tx_clk 0.96ns (right shift) = 0.96ns
>
> This configuration is outside of the recommended RGMII clock skew delays
> and about in the middle of: rgmii-idrx and rgmii-id
>
> Since most embedded systems do not have enough place to introduce
> significant clock skew, rgmii-id is the way to go.
>
> In case this patch breaks network functionality on your system, build
> kernel with enabled MICREL_PHY. If it is still not working then try
> following device tree options:
> 1. Set (or change) phy-mode in DT to:
> phy-mode = "rgmii-id";
> This actives internal delay for both RX and TX.
> 1. Set (or change) phy-mode in DT to:
> phy-mode = "rgmii-idrx";
> This actives internal delay for RX only.
> 3. Use following DT properties:
> phy-mode = "rgmii";
> txen-skew-psec = <0>;
> rxdv-skew-psec = <0>;
> rxd0-skew-psec = <0>;
> rxd1-skew-psec = <0>;
> rxd2-skew-psec = <0>;
> rxd3-skew-psec = <0>;
> rxc-skew-psec = <1860>;
> txc-skew-psec = <1860>;
> This activates the internal delays for RX and TX, with the value as
> the fixup that is removed in this patch.
>
> Signed-off-by: Oleksij Rempel <[email protected]>
Reviewed-by: Andrew Lunn <[email protected]>
Andrew