From adf5132fe8d269c568593e0cd0ed7d5d95d2f938 Mon Sep 17 00:00:00 2001 From: Russell King Date: Fri, 18 Oct 2019 10:21:46 +0100 Subject: net: sfp: eliminate mdelay() from PHY probe Rather than using mdelay() to wait before probing the PHY (which holds several locks, including the rtnl lock), add an extra wait state to the state machine to introduce the 50ms delay without holding any locks. Signed-off-by: Russell King --- drivers/net/phy/sfp.c | 52 +++++++++++++++++++++++++++++++++++++++------------ 1 file changed, 40 insertions(+), 12 deletions(-) diff --git a/drivers/net/phy/sfp.c b/drivers/net/phy/sfp.c index 49919a75e338..316ff719857b 100644 --- a/drivers/net/phy/sfp.c +++ b/drivers/net/phy/sfp.c @@ -54,6 +54,7 @@ enum { SFP_DEV_UP, SFP_S_DOWN = 0, + SFP_S_WAIT, SFP_S_INIT, SFP_S_WAIT_LOS, SFP_S_LINK_UP, @@ -110,6 +111,7 @@ static const char *event_to_str(unsigned short event) static const char * const sm_state_strings[] = { [SFP_S_DOWN] = "down", + [SFP_S_WAIT] = "wait", [SFP_S_INIT] = "init", [SFP_S_WAIT_LOS] = "wait_los", [SFP_S_LINK_UP] = "link_up", @@ -141,6 +143,7 @@ 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) @@ -161,9 +164,6 @@ static const enum gpiod_flags gpio_flags[] = { */ #define SFP_PHY_ADDR 22 -/* Give this long for the PHY to reset. */ -#define T_PHY_RESET_MS 50 - struct sff_data { unsigned int gpios; bool (*module_supported)(const struct sfp_eeprom_id *id); @@ -1267,8 +1267,6 @@ static void sfp_sm_probe_phy(struct sfp *sfp) struct phy_device *phy; int err; - msleep(T_PHY_RESET_MS); - phy = mdiobus_scan(sfp->i2c_mii, SFP_PHY_ADDR); if (phy == ERR_PTR(-ENODEV)) { dev_info(sfp->dev, "no PHY detected\n"); @@ -1623,6 +1621,8 @@ static void sfp_sm_module(struct sfp *sfp, unsigned int event) static void sfp_sm_main(struct sfp *sfp, unsigned int event) { + unsigned long timeout; + /* Some events are global */ if (sfp->sm_state != SFP_S_DOWN && (sfp->sm_mod_state != SFP_MOD_PRESENT || @@ -1640,17 +1640,45 @@ static void sfp_sm_main(struct sfp *sfp, unsigned int event) /* The main state machine */ switch (sfp->sm_state) { case SFP_S_DOWN: - if (sfp->sm_mod_state == SFP_MOD_PRESENT && - sfp->sm_dev_state == SFP_DEV_UP) { - sfp_sm_mod_init(sfp); - sfp_sm_probe_for_phy(sfp); + if (sfp->sm_mod_state != SFP_MOD_PRESENT || + sfp->sm_dev_state != SFP_DEV_UP) + break; + + sfp_sm_mod_init(sfp); + + /* Initialise the fault clearance retries */ + sfp->sm_retries = 5; + + /* We need to check the TX_FAULT state, which is not defined + * while TX_DISABLE is asserted. The earliest we want to do + * anything (such as probe for a PHY) is 50ms. + */ + sfp_sm_next(sfp, SFP_S_WAIT, T_WAIT); + break; + case SFP_S_WAIT: + if (event != SFP_E_TIMEOUT) + break; + + sfp_sm_probe_for_phy(sfp); + + 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. */ - sfp_sm_next(sfp, SFP_S_INIT, T_INIT_JIFFIES); - sfp->sm_retries = 5; + timeout = T_INIT_JIFFIES; + if (timeout > T_WAIT) + timeout -= T_WAIT; + else + timeout = 1; + + sfp_sm_next(sfp, SFP_S_INIT, timeout); + } else { + /* TX_FAULT is not asserted, assume the module has + * finished initialising. + */ + goto init_done; } break; @@ -1658,7 +1686,7 @@ static void sfp_sm_main(struct sfp *sfp, unsigned int event) if (event == SFP_E_TIMEOUT && sfp->state & SFP_F_TX_FAULT) sfp_sm_fault(sfp, true); else if (event == SFP_E_TIMEOUT || event == SFP_E_TX_CLEAR) - sfp_sm_link_check_los(sfp); + init_done: sfp_sm_link_check_los(sfp); break; case SFP_S_WAIT_LOS: -- cgit