From fb56cd08880aff8fb030e684fa4311bef712a499 Mon Sep 17 00:00:00 2001 From: Russell King Date: Tue, 5 Nov 2019 13:02:30 +0000 Subject: [PATCH 633/660] net: sfp: allow sfp to probe slow to initialise GPON modules Some GPON modules (e.g. Huawei MA5671A) take a significant amount of time to start responding on the I2C bus, contary to the SFF specifications. Work around this by implementing a two-level timeout strategy, where we initially quickly retry for the module, and then use a slower retry after we exceed a maximum number of quick attempts. Signed-off-by: Russell King --- drivers/net/phy/sfp.c | 38 ++++++++++++++++++++++++++++---------- 1 file changed, 28 insertions(+), 10 deletions(-) --- a/drivers/net/phy/sfp.c +++ b/drivers/net/phy/sfp.c @@ -167,9 +167,12 @@ static const enum gpiod_flags gpio_flags * The SFF-8472 specifies t_serial ("Time from power on until module is * ready for data transmission over the two wire serial bus.") as 300ms. */ -#define T_SERIAL msecs_to_jiffies(300) -#define T_HPOWER_LEVEL msecs_to_jiffies(300) -#define T_PROBE_RETRY msecs_to_jiffies(100) +#define T_SERIAL msecs_to_jiffies(300) +#define T_HPOWER_LEVEL msecs_to_jiffies(300) +#define T_PROBE_RETRY_INIT msecs_to_jiffies(100) +#define R_PROBE_RETRY_INIT 10 +#define T_PROBE_RETRY_SLOW msecs_to_jiffies(5000) +#define R_PROBE_RETRY_SLOW 12 /* SFP modules appear to always have their PHY configured for bus address * 0x56 (which with mdio-i2c, translates to a PHY address of 22). @@ -204,6 +207,8 @@ struct sfp { struct delayed_work timeout; struct mutex sm_mutex; /* Protects state machine */ unsigned char sm_mod_state; + unsigned char sm_mod_tries_init; + unsigned char sm_mod_tries; unsigned char sm_dev_state; unsigned short sm_state; unsigned int sm_retries; @@ -1457,7 +1462,7 @@ static int sfp_sm_mod_hpower(struct sfp return 0; } -static int sfp_sm_mod_probe(struct sfp *sfp) +static int sfp_sm_mod_probe(struct sfp *sfp, bool report) { /* SFP module inserted - read I2C data */ struct sfp_eeprom_id id; @@ -1467,7 +1472,8 @@ static int sfp_sm_mod_probe(struct sfp * ret = sfp_read(sfp, false, 0, &id, sizeof(id)); if (ret < 0) { - dev_err(sfp->dev, "failed to read EEPROM: %d\n", ret); + if (report) + dev_err(sfp->dev, "failed to read EEPROM: %d\n", ret); return -EAGAIN; } @@ -1614,8 +1620,11 @@ static void sfp_sm_module(struct sfp *sf switch (sfp->sm_mod_state) { default: - if (event == SFP_E_INSERT) + if (event == SFP_E_INSERT) { sfp_sm_mod_next(sfp, SFP_MOD_PROBE, T_SERIAL); + sfp->sm_mod_tries_init = R_PROBE_RETRY_INIT; + sfp->sm_mod_tries = R_PROBE_RETRY_SLOW; + } break; case SFP_MOD_PROBE: @@ -1623,10 +1632,19 @@ static void sfp_sm_module(struct sfp *sf if (event != SFP_E_TIMEOUT) break; - err = sfp_sm_mod_probe(sfp); + err = sfp_sm_mod_probe(sfp, sfp->sm_mod_tries == 1); if (err == -EAGAIN) { - sfp_sm_set_timer(sfp, T_PROBE_RETRY); - break; + if (sfp->sm_mod_tries_init && + --sfp->sm_mod_tries_init) { + sfp_sm_set_timer(sfp, T_PROBE_RETRY_INIT); + break; + } else if (sfp->sm_mod_tries && --sfp->sm_mod_tries) { + if (sfp->sm_mod_tries == R_PROBE_RETRY_SLOW - 1) + dev_warn(sfp->dev, + "please wait, module slow to respond\n"); + sfp_sm_set_timer(sfp, T_PROBE_RETRY_SLOW); + break; + } } if (err < 0) { sfp_sm_mod_next(sfp, SFP_MOD_ERROR, 0); @@ -1661,7 +1679,7 @@ static void sfp_sm_module(struct sfp *sf sfp_module_remove(sfp->sfp_bus); sfp_sm_mod_next(sfp, SFP_MOD_ERROR, 0); } else { - sfp_sm_set_timer(sfp, T_PROBE_RETRY); + sfp_sm_set_timer(sfp, T_PROBE_RETRY_INIT); } break; }