From: Grygorii Strashko grygorii.strashko@ti.com
[ Upstream commit 0b01db274028f5acd207332686ffc92ac77491ac ]
Introduce the W/A for packet errors seen with short cables (<1m) between two DP83867 PHYs.
The W/A recommended by DM requires FFE Equalizer Configuration tuning by writing value 0x0E81 to DSP_FFE_CFG register (0x012C), surrounded by hard and soft resets as follows:
write_reg(0x001F, 0x8000); //hard reset write_reg(DSP_FFE_CFG, 0x0E81); write_reg(0x001F, 0x4000); //soft reset
Since DP83867 PHY DM says "Changing this register to 0x0E81, will not affect Long Cable performance.", enable the W/A by default.
Fixes: 2a10154abcb7 ("net: phy: dp83867: Add TI dp83867 phy") Signed-off-by: Grygorii Strashko grygorii.strashko@ti.com Signed-off-by: Siddharth Vadapalli s-vadapalli@ti.com Reviewed-by: Simon Horman simon.horman@corigine.com Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/net/phy/dp83867.c | 22 +++++++++++++++++++++- 1 file changed, 21 insertions(+), 1 deletion(-)
diff --git a/drivers/net/phy/dp83867.c b/drivers/net/phy/dp83867.c index 783e30451e30d..6230dd5e29902 100644 --- a/drivers/net/phy/dp83867.c +++ b/drivers/net/phy/dp83867.c @@ -41,6 +41,7 @@ #define DP83867_STRAP_STS1 0x006E #define DP83867_STRAP_STS2 0x006f #define DP83867_RGMIIDCTL 0x0086 +#define DP83867_DSP_FFE_CFG 0x012c #define DP83867_RXFCFG 0x0134 #define DP83867_RXFPMD1 0x0136 #define DP83867_RXFPMD2 0x0137 @@ -841,8 +842,27 @@ static int dp83867_phy_reset(struct phy_device *phydev)
usleep_range(10, 20);
- return phy_modify(phydev, MII_DP83867_PHYCTRL, + err = phy_modify(phydev, MII_DP83867_PHYCTRL, DP83867_PHYCR_FORCE_LINK_GOOD, 0); + if (err < 0) + return err; + + /* Configure the DSP Feedforward Equalizer Configuration register to + * improve short cable (< 1 meter) performance. This will not affect + * long cable performance. + */ + err = phy_write_mmd(phydev, DP83867_DEVADDR, DP83867_DSP_FFE_CFG, + 0x0e81); + if (err < 0) + return err; + + err = phy_write(phydev, DP83867_CTRL, DP83867_SW_RESTART); + if (err < 0) + return err; + + usleep_range(10, 20); + + return 0; }
static void dp83867_link_change_notify(struct phy_device *phydev)