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Date:   Thu, 11 May 2023 12:07:06 +0200
From:   Simon Horman <simon.horman@corigine.com>
To:     Siddharth Vadapalli <s-vadapalli@ti.com>
Cc:     andrew@lunn.ch, hkallweit1@gmail.com, linux@armlinux.org.uk,
        davem@davemloft.net, edumazet@google.com, kuba@kernel.org,
        pabeni@redhat.com, netdev@vger.kernel.org,
        linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org,
        srk@ti.com
Subject: Re: [PATCH net v3] net: phy: dp83867: add w/a for packet errors seen
 with short cables
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References: <20230510125139.646222-1-s-vadapalli@ti.com>
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On Wed, May 10, 2023 at 06:21:39PM +0530, Siddharth Vadapalli wrote:
> 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>

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