[PATCH net-next v4 0/2] net: phy: at803x: Update delays for RGMII modes

[PATCH net-next v4 0/2] net: phy: at803x: Update delays for RGMII modes

[Vinod Koul]

Peter[1] reported that patch cd28d1d6e52e: ("net: phy: at803x: Disable
phy delay for RGMII mode") caused regression on am335x-evmsk board.
This board expects the Phy delay to be enabled but specified RGMII mode
which refers to delays being disabled. So fix this by disabling delay only
for RGMII mode and enable for RGMII_ID and RGMII_TXID/RXID modes.

While at it, as pointed by Dave, don't inline the helpers.

[1]: https://www.spinics.net/lists/netdev/msg550749.html

Changes in v4:
 - fix log & comments nbased on Marc's feedback

Vinod Koul (2):
  net: phy: at803x: don't inline helpers
  net: phy: at803x: disable delay only for RGMII mode

 drivers/net/phy/at803x.c | 57 +++++++++++++++++++++++++++++++---------
 1 file changed, 44 insertions(+), 13 deletions(-)

-- 
2.20.1

[PATCH net-next v4 1/2] net: phy: at803x: don't inline helpers

[Vinod Koul]

Some helpers were declared with the "inline" function specifier.
It is preferable to let the compiler pick the right optimizations,
so drop the specifier for at803x_disable_rx_delay() and
at803x_disable_tx_delay()

Reviewed-by: Niklas Cassel <niklas.cassel@linaro.org>
Tested-by: Peter Ujfalusi <peter.ujflausi@ti.com>
Reviewed-by: Marc Gonzalez <marc.w.gonzalez@free.fr>
Signed-off-by: Vinod Koul <vkoul@kernel.org>
---
 drivers/net/phy/at803x.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/net/phy/at803x.c b/drivers/net/phy/at803x.c
index 8ff12938ab47..c6e7d800fd7a 100644
--- a/drivers/net/phy/at803x.c
+++ b/drivers/net/phy/at803x.c
@@ -110,13 +110,13 @@ static int at803x_debug_reg_mask(struct phy_device *phydev, u16 reg,
 	return phy_write(phydev, AT803X_DEBUG_DATA, val);
 }
 
-static inline int at803x_disable_rx_delay(struct phy_device *phydev)
+static int at803x_disable_rx_delay(struct phy_device *phydev)
 {
 	return at803x_debug_reg_mask(phydev, AT803X_DEBUG_REG_0,
 				     AT803X_DEBUG_RX_CLK_DLY_EN, 0);
 }
 
-static inline int at803x_disable_tx_delay(struct phy_device *phydev)
+static int at803x_disable_tx_delay(struct phy_device *phydev)
 {
 	return at803x_debug_reg_mask(phydev, AT803X_DEBUG_REG_5,
 				     AT803X_DEBUG_TX_CLK_DLY_EN, 0);
-- 
2.20.1

[PATCH net-next v4 2/2] net: phy: at803x: disable delay only for RGMII mode

[Vinod Koul]

Per "Documentation/devicetree/bindings/net/ethernet.txt" RGMII mode
should not have delay in PHY whereas RGMII_ID and RGMII_RXID/RGMII_TXID
can have delay in PHY.

So disable the delay only for RGMII mode and enable for other modes.
Also treat the default case as disabled delays.

Fixes: cd28d1d6e52e: ("net: phy: at803x: Disable phy delay for RGMII mode")
Reported-by: Peter Ujfalusi <peter.ujfalusi@ti.com>
Reviewed-by: Niklas Cassel <niklas.cassel@linaro.org>
Tested-by: Peter Ujfalusi <peter.ujflausi@ti.com>
Signed-off-by: Vinod Koul <vkoul@kernel.org>
---
 drivers/net/phy/at803x.c | 53 +++++++++++++++++++++++++++++++---------
 1 file changed, 42 insertions(+), 11 deletions(-)

diff --git a/drivers/net/phy/at803x.c b/drivers/net/phy/at803x.c
index c6e7d800fd7a..a37532aac4b4 100644
--- a/drivers/net/phy/at803x.c
+++ b/drivers/net/phy/at803x.c
@@ -110,6 +110,18 @@ static int at803x_debug_reg_mask(struct phy_device *phydev, u16 reg,
 	return phy_write(phydev, AT803X_DEBUG_DATA, val);
 }
 
+static int at803x_enable_rx_delay(struct phy_device *phydev)
+{
+	return at803x_debug_reg_mask(phydev, AT803X_DEBUG_REG_0, 0,
+				     AT803X_DEBUG_RX_CLK_DLY_EN);
+}
+
+static int at803x_enable_tx_delay(struct phy_device *phydev)
+{
+	return at803x_debug_reg_mask(phydev, AT803X_DEBUG_REG_5, 0,
+				     AT803X_DEBUG_TX_CLK_DLY_EN);
+}
+
 static int at803x_disable_rx_delay(struct phy_device *phydev)
 {
 	return at803x_debug_reg_mask(phydev, AT803X_DEBUG_REG_0,
@@ -255,23 +267,42 @@ static int at803x_config_init(struct phy_device *phydev)
 	if (ret < 0)
 		return ret;
 
-	if (phydev->interface == PHY_INTERFACE_MODE_RGMII_RXID ||
-			phydev->interface == PHY_INTERFACE_MODE_RGMII_ID ||
-			phydev->interface == PHY_INTERFACE_MODE_RGMII) {
-		ret = at803x_disable_rx_delay(phydev);
+	/* The RX and TX delay default is:
+	 *   after HW reset: RX delay enabled and TX delay disabled
+	 *   after SW reset: RX delay enabled, while TX delay retains the
+	 *   value before reset.
+	 *
+	 * So let's first disable the RX and TX delays in PHY and enable
+	 * them based on the mode selected (this also takes care of RGMII
+	 * mode where we expect delays to be disabled)
+	 */
+
+	ret = at803x_disable_rx_delay(phydev);
+	if (ret < 0)
+		return ret;
+	ret = at803x_disable_tx_delay(phydev);
+	if (ret < 0)
+		return ret;
+
+	if (phydev->interface == PHY_INTERFACE_MODE_RGMII_ID ||
+	    phydev->interface == PHY_INTERFACE_MODE_RGMII_RXID) {
+		/* If RGMII_ID or RGMII_RXID are specified enable RX delay,
+		 * otherwise keep it disabled
+		 */
+		ret = at803x_enable_rx_delay(phydev);
 		if (ret < 0)
 			return ret;
 	}
 
-	if (phydev->interface == PHY_INTERFACE_MODE_RGMII_TXID ||
-			phydev->interface == PHY_INTERFACE_MODE_RGMII_ID ||
-			phydev->interface == PHY_INTERFACE_MODE_RGMII) {
-		ret = at803x_disable_tx_delay(phydev);
-		if (ret < 0)
-			return ret;
+	if (phydev->interface == PHY_INTERFACE_MODE_RGMII_ID ||
+	    phydev->interface == PHY_INTERFACE_MODE_RGMII_TXID) {
+		/* If RGMII_ID or RGMII_TXID are specified enable TX delay,
+		 * otherwise keep it disabled
+		 */
+		ret = at803x_enable_tx_delay(phydev);
 	}
 
-	return 0;
+	return ret;
 }
 
 static int at803x_ack_interrupt(struct phy_device *phydev)
-- 
2.20.1

Re: [PATCH net-next v4 0/2] net: phy: at803x: Update delays for RGMII modes

[David Miller]

From: Vinod Koul <vkoul@kernel.org>
Date: Thu, 21 Feb 2019 15:53:13 +0530

> Peter[1] reported that patch cd28d1d6e52e: ("net: phy: at803x: Disable
> phy delay for RGMII mode") caused regression on am335x-evmsk board.
> This board expects the Phy delay to be enabled but specified RGMII mode
> which refers to delays being disabled. So fix this by disabling delay only
> for RGMII mode and enable for RGMII_ID and RGMII_TXID/RXID modes.
> 
> While at it, as pointed by Dave, don't inline the helpers.
> 
> [1]: https://www.spinics.net/lists/netdev/msg550749.html
> 
> Changes in v4:
>  - fix log & comments nbased on Marc's feedback

Series applied, thanks.