From 17d6aeafe9d8268612d91edc0102659edb382282 Mon Sep 17 00:00:00 2001 From: Matthew Slattery Date: Wed, 23 Dec 2009 13:47:37 +0000 Subject: [PATCH 4/8] sfc: QT2025C: Work around PHY bug If we see the PHY remaining stuck in a link-down state due to PCS being down while PMA/PMD is up, we briefly switch to PMA/PMD loopback and back, which usually unsticks it. Signed-off-by: Ben Hutchings Signed-off-by: David S. Miller --- drivers/net/sfc/qt202x_phy.c | 42 ++++++++++++++++++++++++++++++++++++++++++ 1 files changed, 42 insertions(+), 0 deletions(-) diff --git a/drivers/net/sfc/qt202x_phy.c b/drivers/net/sfc/qt202x_phy.c index 7450e3a..e4590fb 100644 --- a/drivers/net/sfc/qt202x_phy.c +++ b/drivers/net/sfc/qt202x_phy.c @@ -52,11 +52,15 @@ void falcon_qt202x_set_led(struct efx_nic *p, int led, int mode) struct qt202x_phy_data { enum efx_phy_mode phy_mode; + bool bug17190_in_bad_state; + unsigned long bug17190_timer; }; #define QT2022C2_MAX_RESET_TIME 500 #define QT2022C2_RESET_WAIT 10 +#define BUG17190_INTERVAL (2 * HZ) + static int qt2025c_wait_reset(struct efx_nic *efx) { unsigned long timeout = jiffies + 10 * HZ; @@ -96,6 +100,39 @@ static int qt2025c_wait_reset(struct efx_nic *efx) return 0; } +static void qt2025c_bug17190_workaround(struct efx_nic *efx) +{ + struct qt202x_phy_data *phy_data = efx->phy_data; + + /* The PHY can get stuck in a state where it reports PHY_XS and PMA/PMD + * layers up, but PCS down (no block_lock). If we notice this state + * persisting for a couple of seconds, we switch PMA/PMD loopback + * briefly on and then off again, which is normally sufficient to + * recover it. + */ + if (efx->link_state.up || + !efx_mdio_links_ok(efx, MDIO_DEVS_PMAPMD | MDIO_DEVS_PHYXS)) { + phy_data->bug17190_in_bad_state = false; + return; + } + + if (!phy_data->bug17190_in_bad_state) { + phy_data->bug17190_in_bad_state = true; + phy_data->bug17190_timer = jiffies + BUG17190_INTERVAL; + return; + } + + if (time_after_eq(jiffies, phy_data->bug17190_timer)) { + EFX_LOG(efx, "bashing QT2025C PMA/PMD\n"); + efx_mdio_set_flag(efx, MDIO_MMD_PMAPMD, MDIO_CTRL1, + MDIO_PMA_CTRL1_LOOPBACK, true); + msleep(100); + efx_mdio_set_flag(efx, MDIO_MMD_PMAPMD, MDIO_CTRL1, + MDIO_PMA_CTRL1_LOOPBACK, false); + phy_data->bug17190_timer = jiffies + BUG17190_INTERVAL; + } +} + static int qt202x_reset_phy(struct efx_nic *efx) { int rc; @@ -144,6 +181,8 @@ static int qt202x_phy_probe(struct efx_nic *efx) return -ENOMEM; efx->phy_data = phy_data; phy_data->phy_mode = efx->phy_mode; + phy_data->bug17190_in_bad_state = false; + phy_data->bug17190_timer = 0; efx->mdio.mmds = QT202X_REQUIRED_DEVS; efx->mdio.mode_support = MDIO_SUPPORTS_C45 | MDIO_EMULATE_C22; @@ -184,6 +223,9 @@ static bool qt202x_phy_poll(struct efx_nic *efx) efx->link_state.fd = true; efx->link_state.fc = efx->wanted_fc; + if (efx->phy_type == PHY_TYPE_QT2025C) + qt2025c_bug17190_workaround(efx); + return efx->link_state.up != was_up; } -- 1.6.5.7