| Message ID | 20210511043735.30557-2-o.rempel@pengutronix.de (mailing list archive) |
|---|---|
| State | Not Applicable |
| Delegated to: | Netdev Maintainers |
| Headers | show |
| Series | remove different PHY fixups | expand |
| Context | Check | Description |
|---|---|---|
| netdev/tree_selection | success | Not a local patch |
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 <o.rempel@pengutronix.de> Reviewed-by: Andrew Lunn <andrew@lunn.ch> Andrew
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,
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 <o.rempel@pengutronix.de> --- arch/arm/mach-imx/mach-imx6q.c | 23 ----------------------- 1 file changed, 23 deletions(-)