131 lines
3.7 KiB
Diff
131 lines
3.7 KiB
Diff
From 0fe72afaa31f98ebd71bd6683fc47021105d0157 Mon Sep 17 00:00:00 2001
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From: Russell King <rmk+kernel@armlinux.org.uk>
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Date: Fri, 18 Oct 2019 10:21:46 +0100
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Subject: [PATCH 627/660] net: sfp: eliminate mdelay() from PHY probe
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Rather than using mdelay() to wait before probing the PHY (which holds
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several locks, including the rtnl lock), add an extra wait state to
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the state machine to introduce the 50ms delay without holding any
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locks.
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Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
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---
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drivers/net/phy/sfp.c | 52 +++++++++++++++++++++++++++++++++----------
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1 file changed, 40 insertions(+), 12 deletions(-)
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--- a/drivers/net/phy/sfp.c
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+++ b/drivers/net/phy/sfp.c
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@@ -54,6 +54,7 @@ enum {
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SFP_DEV_UP,
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SFP_S_DOWN = 0,
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+ SFP_S_WAIT,
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SFP_S_INIT,
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SFP_S_WAIT_LOS,
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SFP_S_LINK_UP,
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@@ -110,6 +111,7 @@ static const char *event_to_str(unsigned
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static const char * const sm_state_strings[] = {
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[SFP_S_DOWN] = "down",
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+ [SFP_S_WAIT] = "wait",
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[SFP_S_INIT] = "init",
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[SFP_S_WAIT_LOS] = "wait_los",
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[SFP_S_LINK_UP] = "link_up",
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@@ -141,6 +143,7 @@ static const enum gpiod_flags gpio_flags
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GPIOD_ASIS,
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};
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+#define T_WAIT msecs_to_jiffies(50)
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#define T_INIT_JIFFIES msecs_to_jiffies(300)
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#define T_RESET_US 10
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#define T_FAULT_RECOVER msecs_to_jiffies(1000)
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@@ -161,9 +164,6 @@ static const enum gpiod_flags gpio_flags
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*/
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#define SFP_PHY_ADDR 22
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-/* Give this long for the PHY to reset. */
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-#define T_PHY_RESET_MS 50
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-
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struct sff_data {
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unsigned int gpios;
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bool (*module_supported)(const struct sfp_eeprom_id *id);
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@@ -1267,8 +1267,6 @@ static void sfp_sm_probe_phy(struct sfp
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struct phy_device *phy;
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int err;
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- msleep(T_PHY_RESET_MS);
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-
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phy = mdiobus_scan(sfp->i2c_mii, SFP_PHY_ADDR);
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if (phy == ERR_PTR(-ENODEV)) {
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dev_info(sfp->dev, "no PHY detected\n");
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@@ -1623,6 +1621,8 @@ static void sfp_sm_module(struct sfp *sf
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static void sfp_sm_main(struct sfp *sfp, unsigned int event)
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{
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+ unsigned long timeout;
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+
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/* Some events are global */
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if (sfp->sm_state != SFP_S_DOWN &&
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(sfp->sm_mod_state != SFP_MOD_PRESENT ||
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@@ -1640,17 +1640,45 @@ static void sfp_sm_main(struct sfp *sfp,
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/* The main state machine */
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switch (sfp->sm_state) {
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case SFP_S_DOWN:
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- if (sfp->sm_mod_state == SFP_MOD_PRESENT &&
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- sfp->sm_dev_state == SFP_DEV_UP) {
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- sfp_sm_mod_init(sfp);
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- sfp_sm_probe_for_phy(sfp);
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+ if (sfp->sm_mod_state != SFP_MOD_PRESENT ||
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+ sfp->sm_dev_state != SFP_DEV_UP)
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+ break;
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+
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+ sfp_sm_mod_init(sfp);
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+
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+ /* Initialise the fault clearance retries */
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+ sfp->sm_retries = 5;
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+
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+ /* We need to check the TX_FAULT state, which is not defined
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+ * while TX_DISABLE is asserted. The earliest we want to do
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+ * anything (such as probe for a PHY) is 50ms.
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+ */
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+ sfp_sm_next(sfp, SFP_S_WAIT, T_WAIT);
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+ break;
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+
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+ case SFP_S_WAIT:
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+ if (event != SFP_E_TIMEOUT)
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+ break;
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+
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+ sfp_sm_probe_for_phy(sfp);
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+ if (sfp->state & SFP_F_TX_FAULT) {
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/* Wait t_init before indicating that the link is up,
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* provided the current state indicates no TX_FAULT. If
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* TX_FAULT clears before this time, that's fine too.
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*/
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- sfp_sm_next(sfp, SFP_S_INIT, T_INIT_JIFFIES);
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- sfp->sm_retries = 5;
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+ timeout = T_INIT_JIFFIES;
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+ if (timeout > T_WAIT)
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+ timeout -= T_WAIT;
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+ else
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+ timeout = 1;
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+
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+ sfp_sm_next(sfp, SFP_S_INIT, timeout);
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+ } else {
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+ /* TX_FAULT is not asserted, assume the module has
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+ * finished initialising.
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+ */
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+ goto init_done;
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}
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break;
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@@ -1658,7 +1686,7 @@ static void sfp_sm_main(struct sfp *sfp,
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if (event == SFP_E_TIMEOUT && sfp->state & SFP_F_TX_FAULT)
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sfp_sm_fault(sfp, true);
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else if (event == SFP_E_TIMEOUT || event == SFP_E_TX_CLEAR)
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- sfp_sm_link_check_los(sfp);
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+ init_done: sfp_sm_link_check_los(sfp);
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break;
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case SFP_S_WAIT_LOS:
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