From 6c4efe83a0acf6f06c89ae17b885fa5739eb5be7 Mon Sep 17 00:00:00 2001 From: Russell King Date: Mon, 2 Dec 2019 18:20:22 +0000 Subject: [PATCH 4/4] net: sfp: re-attempt probing for phy Some 1000BASE-T PHY modules take a while for the PHY to wake up. Retry the probe a number of times before deciding that the module has no PHY. Tested with: Sourcephotonics SPGBTXCNFC - PHY takes less than 50ms to respond. Champion One 1000SFPT - PHY takes about 200ms to respond. Mikrotik S-RJ01 - no PHY Signed-off-by: Russell King --- drivers/net/phy/sfp.c | 59 ++++++++++++++++++++++++++++++++++++--------------- 1 file changed, 42 insertions(+), 17 deletions(-) --- a/drivers/net/phy/sfp.c +++ b/drivers/net/phy/sfp.c @@ -60,6 +60,7 @@ enum { SFP_S_FAIL, SFP_S_WAIT, SFP_S_INIT, + SFP_S_INIT_PHY, SFP_S_INIT_TX_FAULT, SFP_S_WAIT_LOS, SFP_S_LINK_UP, @@ -124,6 +125,7 @@ static const char * const sm_state_strin [SFP_S_FAIL] = "fail", [SFP_S_WAIT] = "wait", [SFP_S_INIT] = "init", + [SFP_S_INIT_PHY] = "init_phy", [SFP_S_INIT_TX_FAULT] = "init_tx_fault", [SFP_S_WAIT_LOS] = "wait_los", [SFP_S_LINK_UP] = "link_up", @@ -178,6 +180,12 @@ static const enum gpiod_flags gpio_flags #define N_FAULT_INIT 5 #define N_FAULT 5 +/* T_PHY_RETRY is the time interval between attempts to probe the PHY. + * R_PHY_RETRY is the number of attempts. + */ +#define T_PHY_RETRY msecs_to_jiffies(50) +#define R_PHY_RETRY 12 + /* 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 * connect before the I2C bus on MOD DEF 1/2. @@ -233,6 +241,7 @@ struct sfp { unsigned char sm_dev_state; unsigned short sm_state; unsigned char sm_fault_retries; + unsigned char sm_phy_retries; struct sfp_eeprom_id id; unsigned int module_power_mW; @@ -1351,10 +1360,8 @@ static int sfp_sm_probe_phy(struct sfp * int err; phy = get_phy_device(sfp->i2c_mii, SFP_PHY_ADDR, is_c45); - if (phy == ERR_PTR(-ENODEV)) { - dev_info(sfp->dev, "no PHY detected\n"); - return 0; - } + if (phy == ERR_PTR(-ENODEV)) + return PTR_ERR(phy); if (IS_ERR(phy)) { dev_err(sfp->dev, "mdiobus scan returned %ld\n", PTR_ERR(phy)); return PTR_ERR(phy); @@ -1802,6 +1809,7 @@ static void sfp_sm_module(struct sfp *sf static void sfp_sm_main(struct sfp *sfp, unsigned int event) { unsigned long timeout; + int ret; /* Some events are global */ if (sfp->sm_state != SFP_S_DOWN && @@ -1875,22 +1883,39 @@ static void sfp_sm_main(struct sfp *sfp, sfp_sm_fault(sfp, SFP_S_INIT_TX_FAULT, sfp->sm_fault_retries == N_FAULT_INIT); } else if (event == SFP_E_TIMEOUT || event == SFP_E_TX_CLEAR) { - init_done: /* TX_FAULT deasserted or we timed out with TX_FAULT - * clear. Probe for the PHY and check the LOS state. - */ - if (sfp_sm_probe_for_phy(sfp)) { - sfp_sm_next(sfp, SFP_S_FAIL, 0); - break; - } - if (sfp_module_start(sfp->sfp_bus)) { - sfp_sm_next(sfp, SFP_S_FAIL, 0); + init_done: + sfp->sm_phy_retries = R_PHY_RETRY; + goto phy_probe; + } + break; + + case SFP_S_INIT_PHY: + if (event != SFP_E_TIMEOUT) + break; + phy_probe: + /* TX_FAULT deasserted or we timed out with TX_FAULT + * clear. Probe for the PHY and check the LOS state. + */ + ret = sfp_sm_probe_for_phy(sfp); + if (ret == -ENODEV) { + if (--sfp->sm_phy_retries) { + sfp_sm_next(sfp, SFP_S_INIT_PHY, T_PHY_RETRY); break; + } else { + dev_info(sfp->dev, "no PHY detected\n"); } - sfp_sm_link_check_los(sfp); - - /* Reset the fault retry count */ - sfp->sm_fault_retries = N_FAULT; + } else if (ret) { + sfp_sm_next(sfp, SFP_S_FAIL, 0); + break; } + if (sfp_module_start(sfp->sfp_bus)) { + sfp_sm_next(sfp, SFP_S_FAIL, 0); + break; + } + sfp_sm_link_check_los(sfp); + + /* Reset the fault retry count */ + sfp->sm_fault_retries = N_FAULT; break; case SFP_S_INIT_TX_FAULT: