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sfc: QT2025C: Work around PHY bug

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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 <bhutchings@solarflare.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Matthew Slattery 2009-12-23 13:47:37 +00:00 committed by David S. Miller
parent a7ebd27a13
commit 17d6aeafe9
1 changed files with 42 additions and 0 deletions
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42
drivers/net/sfc/qt202x_phy.c
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@ -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;
}