Commit 0b01db27 authored by Grygorii Strashko's avatar Grygorii Strashko Committed by David S. Miller
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net: phy: dp83867: add w/a for packet errors seen with short cables 



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: 2a10154a ("net: phy: dp83867: Add TI dp83867 phy")
Signed-off-by: default avatarGrygorii Strashko <grygorii.strashko@ti.com>
Signed-off-by: default avatarSiddharth Vadapalli <s-vadapalli@ti.com>
Reviewed-by: default avatarSimon Horman <simon.horman@corigine.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent f816b982

drivers/net/phy/dp83867.c

+21 −1
Original line number Diff line number Diff line
@@ -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 +942,27 @@ 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)