[OpenWrt-Devel] [PATCH] ar71xx: fix 100/10mbps ethernet link issues on mynet range extender

Florian Fainelli florian at openwrt.org
Sat Jun 6 02:07:31 EDT 2015


Florian
On Jun 5, 2015 2:18 PM, "Dave Taht" <dave.taht at bufferbloat.net> wrote:
>
> TX delay setting? What else can it do?

This is a delay between the transmit data lines and the transmit clock on a
RGMII interface. Based on PCB designs, this is something that may have to
be configured to align clock and data lines in a way that does not violate
timings and causes packet losses between the MAC and the PHY. These delays
are not valid when a RGMII interface operates at 10 or 100Mbits/sec since
the clock becomes slow enough the rise and fall times of the data lines are
negligable.

>
> My dream has been to find a way to set the tx completion interrupt
> to only return with a soft set rate. So if I had a gigE connection
> but my uplink was only 10Mbits, it would return the interrupt
> after 1.3ms had expired.

What you are referring to here is interrupt coalescing, which is different
and implemented at the Ethernet MAC and DMA engine levels and not all
controllers support that.

>
> this would let me get away entirely from using software rate limiting
> with htb, just program a register once with the uplink rate, and
> let bql and fq_codel handle the rest.
>
> On Wed, Jun 03, 2015 at 05:20:22PM +0200, Christian Lamparter wrote:
> > The mynet range extender hardware is suffering from ethernet
> > link loss when booting with a recent openwrt image. This only
> > happens on 100mbps links, with 1Gbps speed the link was fine.
> >
> > The cause of the problem is that the AR8035 PHY (aka F1E)
> > requires turning on and off the special TX delay setting
> > depending on the speed of the link.
> >
> > The 10mbps mode only needed the proper pll value, which was
> > extracted from the vendor code.
> >
> > Reported-by: Pascal Paradis
> > Signed-off-by: Christian Lamparter <chunkeey at googlemail.com>
> > ---
> >  .../ar71xx/files/arch/mips/ath79/mach-mynet-rext.c | 20 ++++++++
> >  ...t-phy-at803x-allow-to-configure-via-pdata.patch | 53
++++++++++++++++++++--
> >  2 files changed, 69 insertions(+), 4 deletions(-)
> >
> > diff --git
a/target/linux/ar71xx/files/arch/mips/ath79/mach-mynet-rext.c
b/target/linux/ar71xx/files/arch/mips/ath79/mach-mynet-rext.c
> > index 02d168e..3d48ca8 100644
> > --- a/target/linux/ar71xx/files/arch/mips/ath79/mach-mynet-rext.c
> > +++ b/target/linux/ar71xx/files/arch/mips/ath79/mach-mynet-rext.c
> > @@ -14,6 +14,7 @@
> >  #include <linux/platform_device.h>
> >  #include <linux/ath9k_platform.h>
> >  #include <linux/ar8216_platform.h>
> > +#include <linux/platform_data/phy-at803x.h>
> >
> >  #include <asm/mach-ath79/ar71xx_regs.h>
> >
> > @@ -124,6 +125,21 @@ static struct gpio_keys_button
mynet_rext_gpio_keys[] __initdata = {
> >       },
> >  };
> >
> > +static struct at803x_platform_data mynet_rext_at803x_data = {
> > +     .disable_smarteee = 0,
> > +     .enable_rgmii_rx_delay = 1,
> > +     .enable_rgmii_tx_delay = 0,
> > +     .fixup_rgmii_tx_delay = 1,
> > +};
> > +
> > +static struct mdio_board_info mynet_rext_mdio0_info[] = {
> > +        {
> > +                .bus_id = "ag71xx-mdio.0",
> > +                .phy_addr = 4,
> > +                .platform_data = &mynet_rext_at803x_data,
> > +        },
> > +};
> > +
> >  static void mynet_rext_get_mac(const char *name, char *mac)
> >  {
> >       u8 *nvram = (u8 *) KSEG1ADDR(MYNET_REXT_NVRAM_ADDR);
> > @@ -169,12 +185,16 @@ static void __init mynet_rext_setup(void)
> >
> >       ath79_register_mdio(0, 0x0);
> >
> > +     mdiobus_register_board_info(mynet_rext_mdio0_info,
> > +                                 ARRAY_SIZE(mynet_rext_mdio0_info));
> > +
> >       /* LAN */
> >       mynet_rext_get_mac("et0macaddr=", ath79_eth0_data.mac_addr);
> >
> >       /* GMAC0 is connected to an external PHY on Port 4 */
> >       ath79_eth0_data.phy_if_mode = PHY_INTERFACE_MODE_RGMII;
> >       ath79_eth0_data.phy_mask = BIT(4);
> > +     ath79_eth0_pll_data.pll_10   = 0x00001313; /* athrs_mac.c */
> >       ath79_eth0_pll_data.pll_1000 = 0x0e000000; /* athrs_mac.c */
> >       ath79_eth0_data.mii_bus_dev = &ath79_mdio0_device.dev;
> >       ath79_register_eth(0);
> > diff --git
a/target/linux/ar71xx/patches-3.18/425-net-phy-at803x-allow-to-configure-via-pdata.patch
b/target/linux/ar71xx/patches-3.18/425-net-phy-at803x-allow-to-configure-via-pdata.patch
> > index babc695..d046ede 100644
> > ---
a/target/linux/ar71xx/patches-3.18/425-net-phy-at803x-allow-to-configure-via-pdata.patch
> > +++
b/target/linux/ar71xx/patches-3.18/425-net-phy-at803x-allow-to-configure-via-pdata.patch
> > @@ -32,6 +32,14 @@
> >   #define AT803X_DEBUG_SYSTEM_MODE_CTRL               0x05
> >   #define AT803X_DEBUG_RGMII_TX_CLK_DLY               BIT(8)
> >
> > +@@ -50,6 +60,7 @@ MODULE_LICENSE("GPL");
> > + struct at803x_priv {
> > +     bool phy_reset:1;
> > +     struct gpio_desc *gpiod_reset;
> > ++    int prev_speed;
> > + };
> > +
> > + struct at803x_context {
> >  @@ -61,6 +71,43 @@ struct at803x_context {
> >       u16 led_control;
> >   };
> > @@ -120,16 +128,53 @@
> >       return 0;
> >   }
> >
> > +@@ -258,6 +334,8 @@ static int at803x_config_intr(struct phy
> > + static void at803x_link_change_notify(struct phy_device *phydev)
> > + {
> > +     struct at803x_priv *priv = phydev->priv;
> > ++    struct at803x_platform_data *pdata;
> > ++    pdata = dev_get_platdata(&phydev->dev);
> > +
> > +     /*
> > +      * Conduct a hardware reset for AT8030 every time a link loss is
> > +@@ -287,6 +365,26 @@ static void at803x_link_change_notify(st
> > +             } else {
> > +                     priv->phy_reset = false;
> > +             }
> > ++    }
> > ++    if (pdata->fixup_rgmii_tx_delay &&
> > ++        phydev->speed != priv->prev_speed) {
> > ++            switch (phydev->speed) {
> > ++            case SPEED_10:
> > ++            case SPEED_100:
> > ++                    at803x_dbg_reg_set(phydev,
> > ++                            AT803X_DEBUG_SYSTEM_MODE_CTRL,
> > ++                            AT803X_DEBUG_RGMII_TX_CLK_DLY);
> > ++                    break;
> > ++            case SPEED_1000:
> > ++                    at803x_dbg_reg_clr(phydev,
> > ++                            AT803X_DEBUG_SYSTEM_MODE_CTRL,
> > ++                            AT803X_DEBUG_RGMII_TX_CLK_DLY);
> > ++                    break;
> > ++            default:
> > ++                    break;
> > ++            }
> > ++
> > ++            priv->prev_speed = phydev->speed;
> > +     }
> > + }
> > +
> >  --- /dev/null
> >  +++ b/include/linux/platform_data/phy-at803x.h
> > -@@ -0,0 +1,10 @@
> > +@@ -0,0 +1,11 @@
> >  +#ifndef _PHY_AT803X_PDATA_H
> >  +#define _PHY_AT803X_PDATA_H
> >  +
> >  +struct at803x_platform_data {
> > -+       int disable_smarteee:1;
> > -+       int enable_rgmii_tx_delay:1;
> > -+       int enable_rgmii_rx_delay:1;
> > ++    int disable_smarteee:1;
> > ++    int enable_rgmii_tx_delay:1;
> > ++    int enable_rgmii_rx_delay:1;
> > ++    int fixup_rgmii_tx_delay:1;
> >  +};
> >  +
> >  +#endif /* _PHY_AT803X_PDATA_H */
> > --
> > 2.1.4
> > _______________________________________________
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> > openwrt-devel at lists.openwrt.org
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