Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 17d6aeaf authored by Matthew Slattery's avatar Matthew Slattery Committed by David S. Miller
Browse files

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: default avatarBen Hutchings <bhutchings@solarflare.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent a7ebd27a

drivers/net/sfc/qt202x_phy.c

+42 −0
Original line number Diff line number Diff line
@@ -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;

}