[PATCH net v3] net: phy: dp83867: add w/a for packet errors seen with short cables

[Simon Horman]

On Wed, May 10, 2023 at 06:21:39PM +0530, Siddharth Vadapalli wrote:
> From: Grygorii Strashko <grygorii.strashko at 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 at ti.com>
> Signed-off-by: Siddharth Vadapalli <s-vadapalli at ti.com>

Reviewed-by: Simon Horman <simon.horman at corigine.com>