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

From: Simon Horman
Date: Thu May 11 2023 - 06:07:21 EST


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

Reviewed-by: Simon Horman <simon.horman@xxxxxxxxxxxx>