kernel: add backported phy/phylink/sfp patches

Backport the phy/phylink/sfp patches currently queued in netdev or in
mainline necessary to support GPON popular modules, specifically to
support Huawei and Nokia GPON modules.

Signed-off-by: Russell King <linux@armlinux.org.uk>
[jonas.gorski: include kernel version in file names, refresh patches]
Signed-off-by: Jonas Gorski <jonas.gorski@gmail.com>

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: