2021-04-08 18:40:17

by Martin Blumenstingl

[permalink] [raw]
Subject: [PATCH net v2 0/2] lantiq: GSWIP: two more fixes

Hello,

after my last patch got accepted and is now in net as commit
3e6fdeb28f4c33 ("net: dsa: lantiq_gswip: Let GSWIP automatically set
the xMII clock") [0] some more people from the OpenWrt community
(many thanks to everyone involved) helped test the GSWIP driver: [1]

It turns out that the previous fix does not work for all boards.
There's no regression, but it doesn't fix as many problems as I
thought. This is why two more fixes are needed:
- the first one solves many (four known but probably there are
a few extra hidden ones) reported bugs with the GSWIP where no
traffic would flow. Not all circumstances are fully understood
but testing shows that switching away from PHY auto polling
solves all of them
- while investigating the different problems which are addressed
by the first patch some small issues with the existing code were
found. These are addressed by the second patch


Changes since v1 at [0]:
- Don't configure the link parameters in gswip_phylink_mac_config
(as we're using the "modern" way in gswip_phylink_mac_link_up).
Thanks to Andrew for the hint with the phylink documentation.
- Clarify that GSWIP_MII_CFG_RMII_CLK is ignored by the hardware in
the description of the second patch as suggested by Hauke
- Don't set GSWIP_MII_CFG_RGMII_IBS in the second patch as we don't
have any hardware available for testing this. The patch
description now also reflects this.
- Added Andrew's Reviewed-by to the first patch (thank you!)


Best regards,
Martin


[0] https://patchwork.kernel.org/project/netdevbpf/cover/20210406203508.[email protected]/


Martin Blumenstingl (2):
net: dsa: lantiq_gswip: Don't use PHY auto polling
net: dsa: lantiq_gswip: Configure all remaining GSWIP_MII_CFG bits

drivers/net/dsa/lantiq_gswip.c | 202 ++++++++++++++++++++++++++++-----
1 file changed, 174 insertions(+), 28 deletions(-)

--
2.31.1


2021-04-08 18:40:27

by Martin Blumenstingl

[permalink] [raw]
Subject: [PATCH net v2 1/2] net: dsa: lantiq_gswip: Don't use PHY auto polling

PHY auto polling on the GSWIP hardware can be used so link changes
(speed, link up/down, etc.) can be detected automatically. Internally
GSWIP reads the PHY's registers for this functionality. Based on this
automatic detection GSWIP can also automatically re-configure it's port
settings. Unfortunately this auto polling (and configuration) mechanism
seems to cause various issues observed by different people on different
devices:
- FritzBox 7360v2: the two Gbit/s ports (connected to the two internal
PHY11G instances) are working fine but the two Fast Ethernet ports
(using an AR8030 RMII PHY) are completely dead (neither RX nor TX are
received). It turns out that the AR8030 PHY sets the BMSR_ESTATEN bit
as well as the ESTATUS_1000_TFULL and ESTATUS_1000_XFULL bits. This
makes the PHY auto polling state machine (rightfully?) think that the
established link speed (when the other side is Gbit/s capable) is
1Gbit/s.
- None of the Ethernet ports on the Zyxel P-2812HNU-F1 (two are
connected to the internal PHY11G GPHYs while the other three are
external RGMII PHYs) are working. Neither RX nor TX traffic was
observed. It is not clear which part of the PHY auto polling state-
machine caused this.
- FritzBox 7412 (only one LAN port which is connected to one of the
internal GPHYs running in PHY22F / Fast Ethernet mode) was seeing
random disconnects (link down events could be seen). Sometimes all
traffic would stop after such disconnect. It is not clear which part
of the PHY auto polling state-machine cauased this.
- TP-Link TD-W9980 (two ports are connected to the internal GPHYs
running in PHY11G / Gbit/s mode, the other two are external RGMII
PHYs) was affected by similar issues as the FritzBox 7412 just without
the "link down" events

Switch to software based configuration instead of PHY auto polling (and
letting the GSWIP hardware configure the ports automatically) for the
following link parameters:
- link up/down
- link speed
- full/half duplex
- flow control (RX / TX pause)

After a big round of manual testing by various people (who helped test
this on OpenWrt) it turns out that this fixes all reported issues.

Additionally it can be considered more future proof because any
"quirk" which is implemented for a PHY on the driver side can now be
used with the GSWIP hardware as well because Linux is in control of the
link parameters.

As a nice side-effect this also solves a problem where fixed-links were
not supported previously because we were relying on the PHY auto polling
mechanism, which cannot work for fixed-links as there's no PHY from
where it can read the registers. Configuring the link settings on the
GSWIP ports means that we now use the settings from device-tree also for
ports with fixed-links.

Fixes: 14fceff4771e51 ("net: dsa: Add Lantiq / Intel DSA driver for vrx200")
Fixes: 3e6fdeb28f4c33 ("net: dsa: lantiq_gswip: Let GSWIP automatically set the xMII clock")
Cc: [email protected]
Acked-by: Hauke Mehrtens <[email protected]>
Reviewed-by: Andrew Lunn <[email protected]>
Signed-off-by: Martin Blumenstingl <[email protected]>
---
drivers/net/dsa/lantiq_gswip.c | 185 ++++++++++++++++++++++++++++-----
1 file changed, 159 insertions(+), 26 deletions(-)

diff --git a/drivers/net/dsa/lantiq_gswip.c b/drivers/net/dsa/lantiq_gswip.c
index 809dfa3be6bb..126d4ea868ba 100644
--- a/drivers/net/dsa/lantiq_gswip.c
+++ b/drivers/net/dsa/lantiq_gswip.c
@@ -190,6 +190,23 @@
#define GSWIP_PCE_DEFPVID(p) (0x486 + ((p) * 0xA))

#define GSWIP_MAC_FLEN 0x8C5
+#define GSWIP_MAC_CTRL_0p(p) (0x903 + ((p) * 0xC))
+#define GSWIP_MAC_CTRL_0_PADEN BIT(8)
+#define GSWIP_MAC_CTRL_0_FCS_EN BIT(7)
+#define GSWIP_MAC_CTRL_0_FCON_MASK 0x0070
+#define GSWIP_MAC_CTRL_0_FCON_AUTO 0x0000
+#define GSWIP_MAC_CTRL_0_FCON_RX 0x0010
+#define GSWIP_MAC_CTRL_0_FCON_TX 0x0020
+#define GSWIP_MAC_CTRL_0_FCON_RXTX 0x0030
+#define GSWIP_MAC_CTRL_0_FCON_NONE 0x0040
+#define GSWIP_MAC_CTRL_0_FDUP_MASK 0x000C
+#define GSWIP_MAC_CTRL_0_FDUP_AUTO 0x0000
+#define GSWIP_MAC_CTRL_0_FDUP_EN 0x0004
+#define GSWIP_MAC_CTRL_0_FDUP_DIS 0x000C
+#define GSWIP_MAC_CTRL_0_GMII_MASK 0x0003
+#define GSWIP_MAC_CTRL_0_GMII_AUTO 0x0000
+#define GSWIP_MAC_CTRL_0_GMII_MII 0x0001
+#define GSWIP_MAC_CTRL_0_GMII_RGMII 0x0002
#define GSWIP_MAC_CTRL_2p(p) (0x905 + ((p) * 0xC))
#define GSWIP_MAC_CTRL_2_MLEN BIT(3) /* Maximum Untagged Frame Lnegth */

@@ -653,16 +670,13 @@ static int gswip_port_enable(struct dsa_switch *ds, int port,
GSWIP_SDMA_PCTRLp(port));

if (!dsa_is_cpu_port(ds, port)) {
- u32 macconf = GSWIP_MDIO_PHY_LINK_AUTO |
- GSWIP_MDIO_PHY_SPEED_AUTO |
- GSWIP_MDIO_PHY_FDUP_AUTO |
- GSWIP_MDIO_PHY_FCONTX_AUTO |
- GSWIP_MDIO_PHY_FCONRX_AUTO |
- (phydev->mdio.addr & GSWIP_MDIO_PHY_ADDR_MASK);
-
- gswip_mdio_w(priv, macconf, GSWIP_MDIO_PHYp(port));
- /* Activate MDIO auto polling */
- gswip_mdio_mask(priv, 0, BIT(port), GSWIP_MDIO_MDC_CFG0);
+ u32 mdio_phy = 0;
+
+ if (phydev)
+ mdio_phy = phydev->mdio.addr & GSWIP_MDIO_PHY_ADDR_MASK;
+
+ gswip_mdio_mask(priv, GSWIP_MDIO_PHY_ADDR_MASK, mdio_phy,
+ GSWIP_MDIO_PHYp(port));
}

return 0;
@@ -675,14 +689,6 @@ static void gswip_port_disable(struct dsa_switch *ds, int port)
if (!dsa_is_user_port(ds, port))
return;

- if (!dsa_is_cpu_port(ds, port)) {
- gswip_mdio_mask(priv, GSWIP_MDIO_PHY_LINK_DOWN,
- GSWIP_MDIO_PHY_LINK_MASK,
- GSWIP_MDIO_PHYp(port));
- /* Deactivate MDIO auto polling */
- gswip_mdio_mask(priv, BIT(port), 0, GSWIP_MDIO_MDC_CFG0);
- }
-
gswip_switch_mask(priv, GSWIP_FDMA_PCTRL_EN, 0,
GSWIP_FDMA_PCTRLp(port));
gswip_switch_mask(priv, GSWIP_SDMA_PCTRL_EN, 0,
@@ -794,20 +800,31 @@ static int gswip_setup(struct dsa_switch *ds)
gswip_switch_w(priv, BIT(cpu_port), GSWIP_PCE_PMAP2);
gswip_switch_w(priv, BIT(cpu_port), GSWIP_PCE_PMAP3);

- /* disable PHY auto polling */
+ /* Deactivate MDIO PHY auto polling. Some PHYs as the AR8030 have an
+ * interoperability problem with this auto polling mechanism because
+ * their status registers think that the link is in a different state
+ * than it actually is. For the AR8030 it has the BMSR_ESTATEN bit set
+ * as well as ESTATUS_1000_TFULL and ESTATUS_1000_XFULL. This makes the
+ * auto polling state machine consider the link being negotiated with
+ * 1Gbit/s. Since the PHY itself is a Fast Ethernet RMII PHY this leads
+ * to the switch port being completely dead (RX and TX are both not
+ * working).
+ * Also with various other PHY / port combinations (PHY11G GPHY, PHY22F
+ * GPHY, external RGMII PEF7071/7072) any traffic would stop. Sometimes
+ * it would work fine for a few minutes to hours and then stop, on
+ * other device it would no traffic could be sent or received at all.
+ * Testing shows that when PHY auto polling is disabled these problems
+ * go away.
+ */
gswip_mdio_w(priv, 0x0, GSWIP_MDIO_MDC_CFG0);
+
/* Configure the MDIO Clock 2.5 MHz */
gswip_mdio_mask(priv, 0xff, 0x09, GSWIP_MDIO_MDC_CFG1);

- for (i = 0; i < priv->hw_info->max_ports; i++) {
- /* Disable the xMII link */
+ /* Disable the xMII link */
+ for (i = 0; i < priv->hw_info->max_ports; i++)
gswip_mii_mask_cfg(priv, GSWIP_MII_CFG_EN, 0, i);

- /* Automatically select the xMII interface clock */
- gswip_mii_mask_cfg(priv, GSWIP_MII_CFG_RATE_MASK,
- GSWIP_MII_CFG_RATE_AUTO, i);
- }
-
/* enable special tag insertion on cpu port */
gswip_switch_mask(priv, 0, GSWIP_FDMA_PCTRL_STEN,
GSWIP_FDMA_PCTRLp(cpu_port));
@@ -1455,6 +1472,112 @@ static void gswip_phylink_validate(struct dsa_switch *ds, int port,
return;
}

+static void gswip_port_set_link(struct gswip_priv *priv, int port, bool link)
+{
+ u32 mdio_phy;
+
+ if (link)
+ mdio_phy = GSWIP_MDIO_PHY_LINK_UP;
+ else
+ mdio_phy = GSWIP_MDIO_PHY_LINK_DOWN;
+
+ gswip_mdio_mask(priv, GSWIP_MDIO_PHY_LINK_MASK, mdio_phy,
+ GSWIP_MDIO_PHYp(port));
+}
+
+static void gswip_port_set_speed(struct gswip_priv *priv, int port, int speed,
+ phy_interface_t interface)
+{
+ u32 mdio_phy = 0, mii_cfg = 0, mac_ctrl_0 = 0;
+
+ switch (speed) {
+ case SPEED_10:
+ mdio_phy = GSWIP_MDIO_PHY_SPEED_M10;
+
+ if (interface == PHY_INTERFACE_MODE_RMII)
+ mii_cfg = GSWIP_MII_CFG_RATE_M50;
+ else
+ mii_cfg = GSWIP_MII_CFG_RATE_M2P5;
+
+ mac_ctrl_0 = GSWIP_MAC_CTRL_0_GMII_MII;
+ break;
+
+ case SPEED_100:
+ mdio_phy = GSWIP_MDIO_PHY_SPEED_M100;
+
+ if (interface == PHY_INTERFACE_MODE_RMII)
+ mii_cfg = GSWIP_MII_CFG_RATE_M50;
+ else
+ mii_cfg = GSWIP_MII_CFG_RATE_M25;
+
+ mac_ctrl_0 = GSWIP_MAC_CTRL_0_GMII_MII;
+ break;
+
+ case SPEED_1000:
+ mdio_phy = GSWIP_MDIO_PHY_SPEED_G1;
+
+ mii_cfg = GSWIP_MII_CFG_RATE_M125;
+
+ mac_ctrl_0 = GSWIP_MAC_CTRL_0_GMII_RGMII;
+ break;
+ }
+
+ gswip_mdio_mask(priv, GSWIP_MDIO_PHY_SPEED_MASK, mdio_phy,
+ GSWIP_MDIO_PHYp(port));
+ gswip_mii_mask_cfg(priv, GSWIP_MII_CFG_RATE_MASK, mii_cfg, port);
+ gswip_switch_mask(priv, GSWIP_MAC_CTRL_0_GMII_MASK, mac_ctrl_0,
+ GSWIP_MAC_CTRL_0p(port));
+}
+
+static void gswip_port_set_duplex(struct gswip_priv *priv, int port, int duplex)
+{
+ u32 mac_ctrl_0, mdio_phy;
+
+ if (duplex == DUPLEX_FULL) {
+ mac_ctrl_0 = GSWIP_MAC_CTRL_0_FDUP_EN;
+ mdio_phy = GSWIP_MDIO_PHY_FDUP_EN;
+ } else {
+ mac_ctrl_0 = GSWIP_MAC_CTRL_0_FDUP_DIS;
+ mdio_phy = GSWIP_MDIO_PHY_FDUP_DIS;
+ }
+
+ gswip_switch_mask(priv, GSWIP_MAC_CTRL_0_FDUP_MASK, mac_ctrl_0,
+ GSWIP_MAC_CTRL_0p(port));
+ gswip_mdio_mask(priv, GSWIP_MDIO_PHY_FDUP_MASK, mdio_phy,
+ GSWIP_MDIO_PHYp(port));
+}
+
+static void gswip_port_set_pause(struct gswip_priv *priv, int port,
+ bool tx_pause, bool rx_pause)
+{
+ u32 mac_ctrl_0, mdio_phy;
+
+ if (tx_pause && rx_pause) {
+ mac_ctrl_0 = GSWIP_MAC_CTRL_0_FCON_RXTX;
+ mdio_phy = GSWIP_MDIO_PHY_FCONTX_EN |
+ GSWIP_MDIO_PHY_FCONRX_EN;
+ } else if (tx_pause) {
+ mac_ctrl_0 = GSWIP_MAC_CTRL_0_FCON_TX;
+ mdio_phy = GSWIP_MDIO_PHY_FCONTX_EN |
+ GSWIP_MDIO_PHY_FCONRX_DIS;
+ } else if (rx_pause) {
+ mac_ctrl_0 = GSWIP_MAC_CTRL_0_FCON_RX;
+ mdio_phy = GSWIP_MDIO_PHY_FCONTX_DIS |
+ GSWIP_MDIO_PHY_FCONRX_EN;
+ } else {
+ mac_ctrl_0 = GSWIP_MAC_CTRL_0_FCON_NONE;
+ mdio_phy = GSWIP_MDIO_PHY_FCONTX_DIS |
+ GSWIP_MDIO_PHY_FCONRX_DIS;
+ }
+
+ gswip_switch_mask(priv, GSWIP_MAC_CTRL_0_FCON_MASK,
+ mac_ctrl_0, GSWIP_MAC_CTRL_0p(port));
+ gswip_mdio_mask(priv,
+ GSWIP_MDIO_PHY_FCONTX_MASK |
+ GSWIP_MDIO_PHY_FCONRX_MASK,
+ mdio_phy, GSWIP_MDIO_PHYp(port));
+}
+
static void gswip_phylink_mac_config(struct dsa_switch *ds, int port,
unsigned int mode,
const struct phylink_link_state *state)
@@ -1511,6 +1634,9 @@ static void gswip_phylink_mac_link_down(struct dsa_switch *ds, int port,
struct gswip_priv *priv = ds->priv;

gswip_mii_mask_cfg(priv, GSWIP_MII_CFG_EN, 0, port);
+
+ if (!dsa_is_cpu_port(ds, port))
+ gswip_port_set_link(priv, port, false);
}

static void gswip_phylink_mac_link_up(struct dsa_switch *ds, int port,
@@ -1522,6 +1648,13 @@ static void gswip_phylink_mac_link_up(struct dsa_switch *ds, int port,
{
struct gswip_priv *priv = ds->priv;

+ if (!dsa_is_cpu_port(ds, port)) {
+ gswip_port_set_link(priv, port, true);
+ gswip_port_set_speed(priv, port, speed, interface);
+ gswip_port_set_duplex(priv, port, duplex);
+ gswip_port_set_pause(priv, port, tx_pause, rx_pause);
+ }
+
gswip_mii_mask_cfg(priv, 0, GSWIP_MII_CFG_EN, port);
}

--
2.31.1

2021-04-08 18:40:56

by Martin Blumenstingl

[permalink] [raw]
Subject: [PATCH net v2 2/2] net: dsa: lantiq_gswip: Configure all remaining GSWIP_MII_CFG bits

There are a few more bits in the GSWIP_MII_CFG register for which we
did rely on the boot-loader (or the hardware defaults) to set them up
properly.

For some external RMII PHYs we need to select the GSWIP_MII_CFG_RMII_CLK
bit and also we should un-set it for non-RMII PHYs. The
GSWIP_MII_CFG_RMII_CLK bit is ignored for other PHY connection modes.

The GSWIP IP also supports in-band auto-negotiation for RGMII PHYs when
the GSWIP_MII_CFG_RGMII_IBS bit is set. Clear this bit always as there's
no known hardware which uses this (so it is not tested yet).

Clear the xMII isolation bit when set at initialization time if it was
previously set by the bootloader. Not doing so could lead to no traffic
(neither RX nor TX) on a port with this bit set.

While here, also add the GSWIP_MII_CFG_RESET bit. We don't need to
manage it because this bit is self-clearning when set. We still add it
here to get a better overview of the GSWIP_MII_CFG register.

Fixes: 14fceff4771e51 ("net: dsa: Add Lantiq / Intel DSA driver for vrx200")
Cc: [email protected]
Suggested-by: Hauke Mehrtens <[email protected]>
Acked-by: Hauke Mehrtens <[email protected]>
Signed-off-by: Martin Blumenstingl <[email protected]>
---
drivers/net/dsa/lantiq_gswip.c | 19 ++++++++++++++++---
1 file changed, 16 insertions(+), 3 deletions(-)

diff --git a/drivers/net/dsa/lantiq_gswip.c b/drivers/net/dsa/lantiq_gswip.c
index 126d4ea868ba..bf5c62e5c0b0 100644
--- a/drivers/net/dsa/lantiq_gswip.c
+++ b/drivers/net/dsa/lantiq_gswip.c
@@ -93,8 +93,12 @@

/* GSWIP MII Registers */
#define GSWIP_MII_CFGp(p) (0x2 * (p))
+#define GSWIP_MII_CFG_RESET BIT(15)
#define GSWIP_MII_CFG_EN BIT(14)
+#define GSWIP_MII_CFG_ISOLATE BIT(13)
#define GSWIP_MII_CFG_LDCLKDIS BIT(12)
+#define GSWIP_MII_CFG_RGMII_IBS BIT(8)
+#define GSWIP_MII_CFG_RMII_CLK BIT(7)
#define GSWIP_MII_CFG_MODE_MIIP 0x0
#define GSWIP_MII_CFG_MODE_MIIM 0x1
#define GSWIP_MII_CFG_MODE_RMIIP 0x2
@@ -821,9 +825,11 @@ static int gswip_setup(struct dsa_switch *ds)
/* Configure the MDIO Clock 2.5 MHz */
gswip_mdio_mask(priv, 0xff, 0x09, GSWIP_MDIO_MDC_CFG1);

- /* Disable the xMII link */
+ /* Disable the xMII interface and clear it's isolation bit */
for (i = 0; i < priv->hw_info->max_ports; i++)
- gswip_mii_mask_cfg(priv, GSWIP_MII_CFG_EN, 0, i);
+ gswip_mii_mask_cfg(priv,
+ GSWIP_MII_CFG_EN | GSWIP_MII_CFG_ISOLATE,
+ 0, i);

/* enable special tag insertion on cpu port */
gswip_switch_mask(priv, 0, GSWIP_FDMA_PCTRL_STEN,
@@ -1597,6 +1603,9 @@ static void gswip_phylink_mac_config(struct dsa_switch *ds, int port,
break;
case PHY_INTERFACE_MODE_RMII:
miicfg |= GSWIP_MII_CFG_MODE_RMIIM;
+
+ /* Configure the RMII clock as output: */
+ miicfg |= GSWIP_MII_CFG_RMII_CLK;
break;
case PHY_INTERFACE_MODE_RGMII:
case PHY_INTERFACE_MODE_RGMII_ID:
@@ -1609,7 +1618,11 @@ static void gswip_phylink_mac_config(struct dsa_switch *ds, int port,
"Unsupported interface: %d\n", state->interface);
return;
}
- gswip_mii_mask_cfg(priv, GSWIP_MII_CFG_MODE_MASK, miicfg, port);
+
+ gswip_mii_mask_cfg(priv,
+ GSWIP_MII_CFG_MODE_MASK | GSWIP_MII_CFG_RMII_CLK |
+ GSWIP_MII_CFG_RGMII_IBS | GSWIP_MII_CFG_LDCLKDIS,
+ miicfg, port);

switch (state->interface) {
case PHY_INTERFACE_MODE_RGMII_ID:
--
2.31.1

2021-04-08 18:50:22

by Florian Fainelli

[permalink] [raw]
Subject: Re: [PATCH net v2 2/2] net: dsa: lantiq_gswip: Configure all remaining GSWIP_MII_CFG bits



On 4/8/2021 11:38 AM, Martin Blumenstingl wrote:
> There are a few more bits in the GSWIP_MII_CFG register for which we
> did rely on the boot-loader (or the hardware defaults) to set them up
> properly.
>
> For some external RMII PHYs we need to select the GSWIP_MII_CFG_RMII_CLK
> bit and also we should un-set it for non-RMII PHYs. The
> GSWIP_MII_CFG_RMII_CLK bit is ignored for other PHY connection modes.
>
> The GSWIP IP also supports in-band auto-negotiation for RGMII PHYs when
> the GSWIP_MII_CFG_RGMII_IBS bit is set. Clear this bit always as there's
> no known hardware which uses this (so it is not tested yet).
>
> Clear the xMII isolation bit when set at initialization time if it was
> previously set by the bootloader. Not doing so could lead to no traffic
> (neither RX nor TX) on a port with this bit set.
>
> While here, also add the GSWIP_MII_CFG_RESET bit. We don't need to
> manage it because this bit is self-clearning when set. We still add it
> here to get a better overview of the GSWIP_MII_CFG register.
>
> Fixes: 14fceff4771e51 ("net: dsa: Add Lantiq / Intel DSA driver for vrx200")
> Cc: [email protected]
> Suggested-by: Hauke Mehrtens <[email protected]>
> Acked-by: Hauke Mehrtens <[email protected]>
> Signed-off-by: Martin Blumenstingl <[email protected]>

Reviewed-by: Florian Fainelli <[email protected]>
--
Florian

2021-04-08 18:50:27

by Florian Fainelli

[permalink] [raw]
Subject: Re: [PATCH net v2 1/2] net: dsa: lantiq_gswip: Don't use PHY auto polling



On 4/8/2021 11:38 AM, Martin Blumenstingl wrote:
> PHY auto polling on the GSWIP hardware can be used so link changes
> (speed, link up/down, etc.) can be detected automatically. Internally
> GSWIP reads the PHY's registers for this functionality. Based on this
> automatic detection GSWIP can also automatically re-configure it's port
> settings. Unfortunately this auto polling (and configuration) mechanism
> seems to cause various issues observed by different people on different
> devices:
> - FritzBox 7360v2: the two Gbit/s ports (connected to the two internal
> PHY11G instances) are working fine but the two Fast Ethernet ports
> (using an AR8030 RMII PHY) are completely dead (neither RX nor TX are
> received). It turns out that the AR8030 PHY sets the BMSR_ESTATEN bit
> as well as the ESTATUS_1000_TFULL and ESTATUS_1000_XFULL bits. This
> makes the PHY auto polling state machine (rightfully?) think that the
> established link speed (when the other side is Gbit/s capable) is
> 1Gbit/s.
> - None of the Ethernet ports on the Zyxel P-2812HNU-F1 (two are
> connected to the internal PHY11G GPHYs while the other three are
> external RGMII PHYs) are working. Neither RX nor TX traffic was
> observed. It is not clear which part of the PHY auto polling state-
> machine caused this.
> - FritzBox 7412 (only one LAN port which is connected to one of the
> internal GPHYs running in PHY22F / Fast Ethernet mode) was seeing
> random disconnects (link down events could be seen). Sometimes all
> traffic would stop after such disconnect. It is not clear which part
> of the PHY auto polling state-machine cauased this.
> - TP-Link TD-W9980 (two ports are connected to the internal GPHYs
> running in PHY11G / Gbit/s mode, the other two are external RGMII
> PHYs) was affected by similar issues as the FritzBox 7412 just without
> the "link down" events
>
> Switch to software based configuration instead of PHY auto polling (and
> letting the GSWIP hardware configure the ports automatically) for the
> following link parameters:
> - link up/down
> - link speed
> - full/half duplex
> - flow control (RX / TX pause)
>
> After a big round of manual testing by various people (who helped test
> this on OpenWrt) it turns out that this fixes all reported issues.
>
> Additionally it can be considered more future proof because any
> "quirk" which is implemented for a PHY on the driver side can now be
> used with the GSWIP hardware as well because Linux is in control of the
> link parameters.
>
> As a nice side-effect this also solves a problem where fixed-links were
> not supported previously because we were relying on the PHY auto polling
> mechanism, which cannot work for fixed-links as there's no PHY from
> where it can read the registers. Configuring the link settings on the
> GSWIP ports means that we now use the settings from device-tree also for
> ports with fixed-links.
>
> Fixes: 14fceff4771e51 ("net: dsa: Add Lantiq / Intel DSA driver for vrx200")
> Fixes: 3e6fdeb28f4c33 ("net: dsa: lantiq_gswip: Let GSWIP automatically set the xMII clock")
> Cc: [email protected]
> Acked-by: Hauke Mehrtens <[email protected]>
> Reviewed-by: Andrew Lunn <[email protected]>
> Signed-off-by: Martin Blumenstingl <[email protected]>

Reviewed-by: Florian Fainelli <[email protected]>
--
Florian

2021-04-08 22:47:10

by Vladimir Oltean

[permalink] [raw]
Subject: Re: [PATCH net v2 1/2] net: dsa: lantiq_gswip: Don't use PHY auto polling

On Thu, Apr 08, 2021 at 08:38:27PM +0200, Martin Blumenstingl wrote:
> PHY auto polling on the GSWIP hardware can be used so link changes
> (speed, link up/down, etc.) can be detected automatically. Internally
> GSWIP reads the PHY's registers for this functionality. Based on this
> automatic detection GSWIP can also automatically re-configure it's port
> settings. Unfortunately this auto polling (and configuration) mechanism
> seems to cause various issues observed by different people on different
> devices:
> - FritzBox 7360v2: the two Gbit/s ports (connected to the two internal
> PHY11G instances) are working fine but the two Fast Ethernet ports
> (using an AR8030 RMII PHY) are completely dead (neither RX nor TX are
> received). It turns out that the AR8030 PHY sets the BMSR_ESTATEN bit
> as well as the ESTATUS_1000_TFULL and ESTATUS_1000_XFULL bits. This
> makes the PHY auto polling state machine (rightfully?) think that the
> established link speed (when the other side is Gbit/s capable) is
> 1Gbit/s.

Why do you say "rightfully"? The PHY is gigabit capable, and it reports
that via the Extended Status register. This is one of the reasons why
the "advertising" and "supported" link modes are separate concepts,
because even though you support gigabit, you don't advertise it because
you are in RMII mode.

How does turning off the auto polling feature help circumvent the
Atheros PHY reporting "issue"? Do we even know that is the problem, or
is it simply a guess on your part based on something that looked strange?

> - None of the Ethernet ports on the Zyxel P-2812HNU-F1 (two are
> connected to the internal PHY11G GPHYs while the other three are
> external RGMII PHYs) are working. Neither RX nor TX traffic was
> observed. It is not clear which part of the PHY auto polling state-
> machine caused this.

Great.

> - FritzBox 7412 (only one LAN port which is connected to one of the
> internal GPHYs running in PHY22F / Fast Ethernet mode) was seeing
> random disconnects (link down events could be seen). Sometimes all
> traffic would stop after such disconnect. It is not clear which part
> of the PHY auto polling state-machine cauased this.
> - TP-Link TD-W9980 (two ports are connected to the internal GPHYs
> running in PHY11G / Gbit/s mode, the other two are external RGMII
> PHYs) was affected by similar issues as the FritzBox 7412 just without
> the "link down" events
>
> Switch to software based configuration instead of PHY auto polling (and
> letting the GSWIP hardware configure the ports automatically) for the
> following link parameters:
> - link up/down
> - link speed
> - full/half duplex
> - flow control (RX / TX pause)

What does the auto polling feature consist of, exactly? Is there some
sort of microcontroller accessing the MDIO bus simultaneously with
Linux?

> After a big round of manual testing by various people (who helped test
> this on OpenWrt) it turns out that this fixes all reported issues.
>
> Additionally it can be considered more future proof because any
> "quirk" which is implemented for a PHY on the driver side can now be
> used with the GSWIP hardware as well because Linux is in control of the
> link parameters.
>
> As a nice side-effect this also solves a problem where fixed-links were
> not supported previously because we were relying on the PHY auto polling
> mechanism, which cannot work for fixed-links as there's no PHY from
> where it can read the registers. Configuring the link settings on the
> GSWIP ports means that we now use the settings from device-tree also for
> ports with fixed-links.
>
> Fixes: 14fceff4771e51 ("net: dsa: Add Lantiq / Intel DSA driver for vrx200")
> Fixes: 3e6fdeb28f4c33 ("net: dsa: lantiq_gswip: Let GSWIP automatically set the xMII clock")
> Cc: [email protected]
> Acked-by: Hauke Mehrtens <[email protected]>
> Reviewed-by: Andrew Lunn <[email protected]>
> Signed-off-by: Martin Blumenstingl <mar[email protected]>
> ---

2021-04-08 23:51:52

by patchwork-bot+netdevbpf

[permalink] [raw]
Subject: Re: [PATCH net v2 0/2] lantiq: GSWIP: two more fixes

Hello:

This series was applied to netdev/net.git (refs/heads/master):

On Thu, 8 Apr 2021 20:38:26 +0200 you wrote:
> Hello,
>
> after my last patch got accepted and is now in net as commit
> 3e6fdeb28f4c33 ("net: dsa: lantiq_gswip: Let GSWIP automatically set
> the xMII clock") [0] some more people from the OpenWrt community
> (many thanks to everyone involved) helped test the GSWIP driver: [1]
>
> [...]

Here is the summary with links:
- [net,v2,1/2] net: dsa: lantiq_gswip: Don't use PHY auto polling
https://git.kernel.org/netdev/net/c/3e9005be8777
- [net,v2,2/2] net: dsa: lantiq_gswip: Configure all remaining GSWIP_MII_CFG bits
https://git.kernel.org/netdev/net/c/4b5923249b8f

You are awesome, thank you!
--
Deet-doot-dot, I am a bot.
https://korg.docs.kernel.org/patchwork/pwbot.html


2021-04-09 19:44:34

by Martin Blumenstingl

[permalink] [raw]
Subject: Re: [PATCH net v2 1/2] net: dsa: lantiq_gswip: Don't use PHY auto polling

Hello Vladimir,

On Fri, Apr 9, 2021 at 12:46 AM Vladimir Oltean <[email protected]> wrote:
>
> On Thu, Apr 08, 2021 at 08:38:27PM +0200, Martin Blumenstingl wrote:
> > PHY auto polling on the GSWIP hardware can be used so link changes
> > (speed, link up/down, etc.) can be detected automatically. Internally
> > GSWIP reads the PHY's registers for this functionality. Based on this
> > automatic detection GSWIP can also automatically re-configure it's port
> > settings. Unfortunately this auto polling (and configuration) mechanism
> > seems to cause various issues observed by different people on different
> > devices:
> > - FritzBox 7360v2: the two Gbit/s ports (connected to the two internal
> > PHY11G instances) are working fine but the two Fast Ethernet ports
> > (using an AR8030 RMII PHY) are completely dead (neither RX nor TX are
> > received). It turns out that the AR8030 PHY sets the BMSR_ESTATEN bit
> > as well as the ESTATUS_1000_TFULL and ESTATUS_1000_XFULL bits. This
> > makes the PHY auto polling state machine (rightfully?) think that the
> > established link speed (when the other side is Gbit/s capable) is
> > 1Gbit/s.
>
> Why do you say "rightfully"? The PHY is gigabit capable, and it reports
> that via the Extended Status register. This is one of the reasons why
> the "advertising" and "supported" link modes are separate concepts,
> because even though you support gigabit, you don't advertise it because
> you are in RMII mode.
according to the marketing materials of the AR8030 it is a "Ultra
low-power single RMII Fast Ethernet PHY"
based on that I am referring to this PHY as "not Gbit/s capable"
(other PHYs from the AR803x series are Gbit/s capable though)

> How does turning off the auto polling feature help circumvent the
> Atheros PHY reporting "issue"? Do we even know that is the problem, or
> is it simply a guess on your part based on something that looked strange?
I have a patch in my queue (which I'll send for the next -net-next
cycle) which adds "ethtool -d" (.get_regs) support to the GSWIP
driver.
There are multiple status registers, one of them indicates that the
link speed (as result of the auto polling mechanism) is 1Gbit/s

[...]
> > Switch to software based configuration instead of PHY auto polling (and
> > letting the GSWIP hardware configure the ports automatically) for the
> > following link parameters:
> > - link up/down
> > - link speed
> > - full/half duplex
> > - flow control (RX / TX pause)
>
> What does the auto polling feature consist of, exactly? Is there some
> sort of microcontroller accessing the MDIO bus simultaneously with
> Linux?
I believe the answer is yes, but there's no clear description in the
datasheet for a newer GSWIP revision [0]
"Figure 8" on page 41 (or page 39 if you go by the numbers at the
bottom of each page) has a description of the state machine logic.
If I understood Hauke correct the "not fiber" part is only checked for
newer GSWIP revisions

Please note that the datasheet from [0] refers to part number GSW140
which is a stand-alone IC.
The GSWIP driver (currently) supports an older revision (at least two
generations older) of GSWIP which is built into Lantiq xRX200 and
xRX300 SoCs.


Best regards,
Martin


[0] https://www.maxlinear.com/document/index?id=23266&languageid=1033&type=Datasheet&partnumber=GSW140&filename=617930_GSW140_DS_Rev1.7.pdf&part=GSW140