From e5f3a4a56ce2a707b2fb8ce37e4414dcac89c672 Mon Sep 17 00:00:00 2001 From: Martin Blumenstingl Date: Fri, 25 Nov 2016 14:12:00 +0100 Subject: [PATCH 1/2] Documentation: devicetree: clarify usage of the RGMII phy-modes RGMII requires special RX and/or TX delays depending on the actual hardware circuit/wiring. These delays can be added by the MAC, the PHY or the designer of the circuit (the latter means that no delay has to be added by PHY or MAC). There are 4 RGMII phy-modes used describe where a delay should be applied: - rgmii: the RX and TX delays are either added by the MAC (where the exact delay is typically configurable, and can be turned off when no extra delay is needed) or not needed at all (because the hardware wiring adds the delay already). The PHY should neither add the RX nor TX delay in this case. - rgmii-rxid: configures the PHY to enable the RX delay. The MAC should not add the RX delay in this case. - rgmii-txid: configures the PHY to enable the TX delay. The MAC should not add the TX delay in this case. - rgmii-id: combines rgmii-rxid and rgmii-txid and thus configures the PHY to enable the RX and TX delays. The MAC should neither add the RX nor TX delay in this case. Document these cases in the ethernet.txt documentation to make it clear when to use each mode. If applied incorrectly one might end up with MAC and PHY both enabling for example the TX delay, which breaks ethernet TX traffic on 1000Mbit/s links. Signed-off-by: Martin Blumenstingl Reviewed-by: Florian Fainelli Signed-off-by: David S. Miller --- .../devicetree/bindings/net/ethernet.txt | 24 +++++++++++++++---- 1 file changed, 20 insertions(+), 4 deletions(-) diff --git a/Documentation/devicetree/bindings/net/ethernet.txt b/Documentation/devicetree/bindings/net/ethernet.txt index e1d76812419c..05150957ecfd 100644 --- a/Documentation/devicetree/bindings/net/ethernet.txt +++ b/Documentation/devicetree/bindings/net/ethernet.txt @@ -9,10 +9,26 @@ The following properties are common to the Ethernet controllers: - max-speed: number, specifies maximum speed in Mbit/s supported by the device; - max-frame-size: number, maximum transfer unit (IEEE defined MTU), rather than the maximum frame size (there's contradiction in ePAPR). -- phy-mode: string, operation mode of the PHY interface; supported values are - "mii", "gmii", "sgmii", "qsgmii", "tbi", "rev-mii", "rmii", "rgmii", "rgmii-id", - "rgmii-rxid", "rgmii-txid", "rtbi", "smii", "xgmii", "trgmii"; this is now a - de-facto standard property; +- phy-mode: string, operation mode of the PHY interface. This is now a de-facto + standard property; supported values are: + * "mii" + * "gmii" + * "sgmii" + * "qsgmii" + * "tbi" + * "rev-mii" + * "rmii" + * "rgmii" (RX and TX delays are added by the MAC when required) + * "rgmii-id" (RGMII with internal RX and TX delays provided by the PHY, the + MAC should not add the RX or TX delays in this case) + * "rgmii-rxid" (RGMII with internal RX delay provided by the PHY, the MAC + should not add an RX delay in this case) + * "rgmii-txid" (RGMII with internal TX delay provided by the PHY, the MAC + should not add an TX delay in this case) + * "rtbi" + * "smii" + * "xgmii" + * "trgmii" - phy-connection-type: the same as "phy-mode" property but described in ePAPR; - phy-handle: phandle, specifies a reference to a node representing a PHY device; this property is described in ePAPR and so preferred; From e3230494b57ece68750e3e32d3e53d6b00917058 Mon Sep 17 00:00:00 2001 From: Martin Blumenstingl Date: Fri, 25 Nov 2016 14:12:01 +0100 Subject: [PATCH 2/2] net: phy: realtek: fix enabling of the TX-delay for RTL8211F The old logic always enabled the TX-delay when the phy-mode was set to PHY_INTERFACE_MODE_RGMII. There are dedicated phy-modes which tell the PHY driver to enable the RX and/or TX delays: - PHY_INTERFACE_MODE_RGMII should disable the RX and TX delay in the PHY (if required, the MAC should add the delays in this case) - PHY_INTERFACE_MODE_RGMII_ID should enable RX and TX delay in the PHY - PHY_INTERFACE_MODE_RGMII_TXID should enable the TX delay in the PHY - PHY_INTERFACE_MODE_RGMII_RXID should enable the RX delay in the PHY (currently not supported by RTL8211F) With this patch we enable the TX delay for PHY_INTERFACE_MODE_RGMII_ID and PHY_INTERFACE_MODE_RGMII_TXID. Additionally we now explicity disable the TX-delay, which seems to be enabled automatically after a hard-reset of the PHY (by triggering it's reset pin) to get a consistent state (as defined by the phy-mode). This fixes a compatibility problem with some SoCs where the TX-delay was also added by the MAC. With the TX-delay being applied twice the TX clock was off and TX traffic was broken or very slow (<10Mbit/s) on 1000Mbit/s links. Signed-off-by: Martin Blumenstingl Reviewed-by: Florian Fainelli Signed-off-by: David S. Miller --- drivers/net/phy/realtek.c | 20 ++++++++++++-------- 1 file changed, 12 insertions(+), 8 deletions(-) diff --git a/drivers/net/phy/realtek.c b/drivers/net/phy/realtek.c index aadd6e9f54ad..9cbe645e3d89 100644 --- a/drivers/net/phy/realtek.c +++ b/drivers/net/phy/realtek.c @@ -102,15 +102,19 @@ static int rtl8211f_config_init(struct phy_device *phydev) if (ret < 0) return ret; - if (phydev->interface == PHY_INTERFACE_MODE_RGMII) { - /* enable TXDLY */ - phy_write(phydev, RTL8211F_PAGE_SELECT, 0xd08); - reg = phy_read(phydev, 0x11); + phy_write(phydev, RTL8211F_PAGE_SELECT, 0xd08); + reg = phy_read(phydev, 0x11); + + /* enable TX-delay for rgmii-id and rgmii-txid, otherwise disable it */ + if (phydev->interface == PHY_INTERFACE_MODE_RGMII_ID || + phydev->interface == PHY_INTERFACE_MODE_RGMII_TXID) reg |= RTL8211F_TX_DELAY; - phy_write(phydev, 0x11, reg); - /* restore to default page 0 */ - phy_write(phydev, RTL8211F_PAGE_SELECT, 0x0); - } + else + reg &= ~RTL8211F_TX_DELAY; + + phy_write(phydev, 0x11, reg); + /* restore to default page 0 */ + phy_write(phydev, RTL8211F_PAGE_SELECT, 0x0); return 0; }