From 2cd7584b84b6e2732e9b87805f38b89b7b633cbf Mon Sep 17 00:00:00 2001 From: Russell King Date: Tue, 3 Dec 2019 15:22:05 +0000 Subject: net: sfp: avoid tx-fault with Nokia GPON module The Nokia GPON module can hold tx-fault active while it is initialising which can take up to 60s. Avoid this causing the module to be declared faulty after the SFP MSA defined non-cooled module timeout. Signed-off-by: Russell King --- drivers/net/phy/sfp.c | 42 ++++++++++++++++++++++++++++++------------ 1 file changed, 30 insertions(+), 12 deletions(-) diff --git a/drivers/net/phy/sfp.c b/drivers/net/phy/sfp.c index c0b9a8e4e65a..27360d1840b2 100644 --- a/drivers/net/phy/sfp.c +++ b/drivers/net/phy/sfp.c @@ -155,10 +155,20 @@ static const enum gpiod_flags gpio_flags[] = { GPIOD_ASIS, }; -#define T_WAIT msecs_to_jiffies(50) -#define T_INIT_JIFFIES msecs_to_jiffies(300) -#define T_RESET_US 10 -#define T_FAULT_RECOVER msecs_to_jiffies(1000) +/* t_start_up (SFF-8431) or t_init (SFF-8472) is the time required for a + * non-cooled module to initialise its laser safety circuitry. We wait + * an initial T_WAIT period before we check the tx fault to give any PHY + * on board (for a copper SFP) time to initialise. + */ +#define T_WAIT msecs_to_jiffies(50) +#define T_START_UP msecs_to_jiffies(300) +#define T_START_UP_BAD_GPON msecs_to_jiffies(60000) + +/* t_reset is the time required to assert the TX_DISABLE signal to reset + * an indicated TX_FAULT. + */ +#define T_RESET_US 10 +#define T_FAULT_RECOVER msecs_to_jiffies(1000) /* SFP module presence detection is poor: the three MOD DEF signals are * the same length on the PCB, which means it's possible for MOD DEF 0 to @@ -218,6 +228,7 @@ struct sfp { struct sfp_eeprom_id id; unsigned int module_power_mW; + unsigned int module_t_start_up; #if IS_ENABLED(CONFIG_HWMON) struct sfp_diag diag; @@ -1655,6 +1666,12 @@ static int sfp_sm_mod_probe(struct sfp *sfp, bool report) if (ret < 0) return ret; + if (!memcmp(id.base.vendor_name, "ALCATELLUCENT ", 16) && + !memcmp(id.base.vendor_pn, "3FE46541AA ", 16)) + sfp->module_t_start_up = T_START_UP_BAD_GPON; + else + sfp->module_t_start_up = T_START_UP; + return 0; } @@ -1855,11 +1872,12 @@ static void sfp_sm_main(struct sfp *sfp, unsigned int event) break; if (sfp->state & SFP_F_TX_FAULT) { - /* Wait t_init before indicating that the link is up, - * provided the current state indicates no TX_FAULT. If - * TX_FAULT clears before this time, that's fine too. + /* Wait up to t_init (SFF-8472) or t_start_up (SFF-8431) + * from the TX_DISABLE deassertion for the module to + * initialise, which is indicated by TX_FAULT + * deasserting. */ - timeout = T_INIT_JIFFIES; + timeout = sfp->module_t_start_up; if (timeout > T_WAIT) timeout -= T_WAIT; else @@ -1876,8 +1894,8 @@ static void sfp_sm_main(struct sfp *sfp, unsigned int event) case SFP_S_INIT: if (event == SFP_E_TIMEOUT && sfp->state & SFP_F_TX_FAULT) { - /* TX_FAULT is still asserted after t_init, so assume - * there is a fault. + /* TX_FAULT is still asserted after t_init or + * or t_start_up, so assume there is a fault. */ sfp_sm_fault(sfp, SFP_S_INIT_TX_FAULT, sfp->sm_retries == 5); @@ -1896,7 +1914,7 @@ static void sfp_sm_main(struct sfp *sfp, unsigned int event) case SFP_S_INIT_TX_FAULT: if (event == SFP_E_TIMEOUT) { sfp_module_tx_fault_reset(sfp); - sfp_sm_next(sfp, SFP_S_INIT, T_INIT_JIFFIES); + sfp_sm_next(sfp, SFP_S_INIT, sfp->module_t_start_up); } break; @@ -1920,7 +1938,7 @@ static void sfp_sm_main(struct sfp *sfp, unsigned int event) case SFP_S_TX_FAULT: if (event == SFP_E_TIMEOUT) { sfp_module_tx_fault_reset(sfp); - sfp_sm_next(sfp, SFP_S_REINIT, T_INIT_JIFFIES); + sfp_sm_next(sfp, SFP_S_REINIT, sfp->module_t_start_up); } break; -- cgit