diff options
Diffstat (limited to 'target/linux/generic/backport-5.4/729-v5.5-net-sfp-eliminate-mdelay-from-PHY-probe.patch')
| -rw-r--r-- | target/linux/generic/backport-5.4/729-v5.5-net-sfp-eliminate-mdelay-from-PHY-probe.patch | 130 |
1 files changed, 130 insertions, 0 deletions
diff --git a/target/linux/generic/backport-5.4/729-v5.5-net-sfp-eliminate-mdelay-from-PHY-probe.patch b/target/linux/generic/backport-5.4/729-v5.5-net-sfp-eliminate-mdelay-from-PHY-probe.patch new file mode 100644 index 0000000000..5dc92bd10e --- /dev/null +++ b/target/linux/generic/backport-5.4/729-v5.5-net-sfp-eliminate-mdelay-from-PHY-probe.patch @@ -0,0 +1,130 @@ +From 0fe72afaa31f98ebd71bd6683fc47021105d0157 Mon Sep 17 00:00:00 2001 +From: Russell King <rmk+kernel@armlinux.org.uk> +Date: Fri, 18 Oct 2019 10:21:46 +0100 +Subject: [PATCH 627/660] 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 <rmk+kernel@armlinux.org.uk> +--- + drivers/net/phy/sfp.c | 52 +++++++++++++++++++++++++++++++++---------- + 1 file changed, 40 insertions(+), 12 deletions(-) + +--- a/drivers/net/phy/sfp.c ++++ b/drivers/net/phy/sfp.c +@@ -52,6 +52,7 @@ enum { + SFP_DEV_UP, + + SFP_S_DOWN = 0, ++ SFP_S_WAIT, + SFP_S_INIT, + SFP_S_WAIT_LOS, + SFP_S_LINK_UP, +@@ -108,6 +109,7 @@ static const char *event_to_str(unsigned + + 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", +@@ -139,6 +141,7 @@ 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) +@@ -159,9 +162,6 @@ 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); +@@ -1202,8 +1202,6 @@ static void sfp_sm_probe_phy(struct 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"); +@@ -1558,6 +1556,8 @@ static void sfp_sm_module(struct sfp *sf + + 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 || +@@ -1575,17 +1575,45 @@ static void sfp_sm_main(struct sfp *sfp, + /* 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; + +@@ -1593,7 +1621,7 @@ static void sfp_sm_main(struct sfp *sfp, + 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: |