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Diffstat (limited to 'target/linux/generic/backport-4.19/729-v5.5-net-sfp-eliminate-mdelay-from-PHY-probe.patch')
-rw-r--r--target/linux/generic/backport-4.19/729-v5.5-net-sfp-eliminate-mdelay-from-PHY-probe.patch130
1 files changed, 130 insertions, 0 deletions
diff --git a/target/linux/generic/backport-4.19/729-v5.5-net-sfp-eliminate-mdelay-from-PHY-probe.patch b/target/linux/generic/backport-4.19/729-v5.5-net-sfp-eliminate-mdelay-from-PHY-probe.patch
new file mode 100644
index 0000000000..5dc92bd10e
--- /dev/null
+++ b/target/linux/generic/backport-4.19/729-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: