[PATCH 6.7 374/713] net: phy: dp83822: Fix RGMII TX delay configuration

Sasha Levin
2024-03-24T22:53:29Z

From: Tim Pambor <tp@osasysteme.de>

[ Upstream commit c8a5c731fd1223090af57da33838c671a7fc6a78 ]

The logic for enabling the TX clock shift is inverse of enabling the RX
clock shift. The TX clock shift is disabled when DP83822_TX_CLK_SHIFT is
set. Correct the current behavior and always write the delay configuration
to ensure consistent delay settings regardless of bootloader configuration.

Reference: https://www.ti.com/lit/ds/symlink/dp83822i.pdf p. 69

Fixes: 8095295292b5 ("net: phy: DP83822: Add setting the fixed internal delay")
Signed-off-by: Tim Pambor <tp@osasysteme.de>
Link: https://lore.kernel.org/r/20240305110608.104072-1-tp@osasysteme.de
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/net/phy/dp83822.c | 37 ++++++++++++++++++++-----------------
1 file changed, 20 insertions(+), 17 deletions(-)

diff --git a/drivers/net/phy/dp83822.c b/drivers/net/phy/dp83822.c
index b7cb71817780c..29e1cbea6dc0c 100644
--- a/drivers/net/phy/dp83822.c
+++ b/drivers/net/phy/dp83822.c
@@ -380,7 +380,7 @@ static int dp83822_config_init(struct phy_device *phydev)
{
struct dp83822_private *dp83822 = phydev->priv;
struct device *dev = &phydev->mdio.dev;
- int rgmii_delay;
+ int rgmii_delay = 0;
s32 rx_int_delay;
s32 tx_int_delay;
int err = 0;
@@ -390,30 +390,33 @@ static int dp83822_config_init(struct phy_device *phydev)
rx_int_delay = phy_get_internal_delay(phydev, dev, NULL, 0,
true);

- if (rx_int_delay <= 0)
- rgmii_delay = 0;
- else
- rgmii_delay = DP83822_RX_CLK_SHIFT;
+ /* Set DP83822_RX_CLK_SHIFT to enable rx clk internal delay */
+ if (rx_int_delay > 0)
+ rgmii_delay |= DP83822_RX_CLK_SHIFT;

tx_int_delay = phy_get_internal_delay(phydev, dev, NULL, 0,
false);
+
+ /* Set DP83822_TX_CLK_SHIFT to disable tx clk internal delay */
if (tx_int_delay <= 0)
- rgmii_delay &= ~DP83822_TX_CLK_SHIFT;
- else
rgmii_delay |= DP83822_TX_CLK_SHIFT;

- if (rgmii_delay) {
- err = phy_set_bits_mmd(phydev, DP83822_DEVADDR,
- MII_DP83822_RCSR, rgmii_delay);
- if (err)
- return err;
- }
+ err = phy_modify_mmd(phydev, DP83822_DEVADDR, MII_DP83822_RCSR,
+ DP83822_RX_CLK_SHIFT | DP83822_TX_CLK_SHIFT, rgmii_delay);
+ if (err)
+ return err;
+
+ err = phy_set_bits_mmd(phydev, DP83822_DEVADDR,
+ MII_DP83822_RCSR, DP83822_RGMII_MODE_EN);

- phy_set_bits_mmd(phydev, DP83822_DEVADDR,
- MII_DP83822_RCSR, DP83822_RGMII_MODE_EN);
+ if (err)
+ return err;
} else {
- phy_clear_bits_mmd(phydev, DP83822_DEVADDR,
- MII_DP83822_RCSR, DP83822_RGMII_MODE_EN);
+ err = phy_clear_bits_mmd(phydev, DP83822_DEVADDR,
+ MII_DP83822_RCSR, DP83822_RGMII_MODE_EN);
+
+ if (err)
+ return err;
}

if (dp83822->fx_enabled) {
--
2.43.0