Messages in this thread Patch in this message | | | From | Siddharth Vadapalli <> | Subject | [PATCH net v2] net: phy: dp83867: add w/a for packet errors seen with short cables | Date | Tue, 9 May 2023 10:51:24 +0530 |
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From: Grygorii Strashko <grygorii.strashko@ti.com>
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> ---
V1 patch at: https://lore.kernel.org/r/20230508070019.356548-1-s-vadapalli@ti.com
Changes since v1 patch: - Wrap the line invoking phy_write_mmd(), limiting it to 80 characters. - Replace 0X0E81 with 0x0e81 in the call to phy_write_mmd(). - Replace 0X012C with 0x012c in the new define for DP83867_DSP_FFE_CFG.
RFC patch at: https://lore.kernel.org/r/20230425054429.3956535-2-s-vadapalli@ti.com/
Changes since RFC patch: - Change patch subject to PATCH net. - Add Fixes tag. - Check return value of phy_write_mmd().
drivers/net/phy/dp83867.c | 18 +++++++++++++++++- 1 file changed, 17 insertions(+), 1 deletion(-)
diff --git a/drivers/net/phy/dp83867.c b/drivers/net/phy/dp83867.c index d75f526a20a4..bbdcc595715d 100644 --- a/drivers/net/phy/dp83867.c +++ b/drivers/net/phy/dp83867.c @@ -44,6 +44,7 @@ #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 @@ -941,8 +942,23 @@ 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; + + 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) -- 2.25.1
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