From: Russell King <rmk+kernel@armlinux.org.uk>
Date: Wed, 6 Feb 2019 10:52:30 +0000 (+0000)
Subject: net: sfp: do not probe SFP module before we're attached
X-Git-Tag: v4.14.104~24
X-Git-Url: https://www.infradead.org/git/?a=commitdiff_plain;h=c4ba68b8691e4879cc43c37ad395ea529709bf81;p=users%2Fjedix%2Flinux-maple.git

net: sfp: do not probe SFP module before we're attached

[ Upstream commit b5bfc21af5cb3d53f9cee0ef82eaa43762a90f81 ]

When we probe a SFP module, we expect to be able to call the upstream
device's module_insert() function so that the upstream link can be
configured.  However, when the upstream device is delayed, we currently
may end up probing the module before the upstream device is available,
and lose the module_insert() call.

Avoid this by holding off probing the module until the SFP bus is
properly connected to both the SFP socket driver and the upstream
driver.

Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---

diff --git a/drivers/net/phy/sfp-bus.c b/drivers/net/phy/sfp-bus.c
index 7ae815bee52d5..be6016e21d877 100644
--- a/drivers/net/phy/sfp-bus.c
+++ b/drivers/net/phy/sfp-bus.c
@@ -276,6 +276,7 @@ static int sfp_register_bus(struct sfp_bus *bus)
 				return ret;
 		}
 	}
+	bus->socket_ops->attach(bus->sfp);
 	if (bus->started)
 		bus->socket_ops->start(bus->sfp);
 	bus->registered = true;
@@ -289,6 +290,7 @@ static void sfp_unregister_bus(struct sfp_bus *bus)
 	if (bus->registered) {
 		if (bus->started)
 			bus->socket_ops->stop(bus->sfp);
+		bus->socket_ops->detach(bus->sfp);
 		if (bus->phydev && ops && ops->disconnect_phy)
 			ops->disconnect_phy(bus->upstream);
 	}
diff --git a/drivers/net/phy/sfp.c b/drivers/net/phy/sfp.c
index 3165bc7b8e1e4..a1b68b19d9124 100644
--- a/drivers/net/phy/sfp.c
+++ b/drivers/net/phy/sfp.c
@@ -114,6 +114,7 @@ struct sfp {
 
 	struct gpio_desc *gpio[GPIO_MAX];
 
+	bool attached;
 	unsigned int state;
 	struct delayed_work poll;
 	struct delayed_work timeout;
@@ -500,7 +501,7 @@ static void sfp_sm_event(struct sfp *sfp, unsigned int event)
 	 */
 	switch (sfp->sm_mod_state) {
 	default:
-		if (event == SFP_E_INSERT) {
+		if (event == SFP_E_INSERT && sfp->attached) {
 			sfp_module_tx_disable(sfp);
 			sfp_sm_ins_next(sfp, SFP_MOD_PROBE, T_PROBE_INIT);
 		}
@@ -628,6 +629,19 @@ static void sfp_sm_event(struct sfp *sfp, unsigned int event)
 	mutex_unlock(&sfp->sm_mutex);
 }
 
+static void sfp_attach(struct sfp *sfp)
+{
+	sfp->attached = true;
+	if (sfp->state & SFP_F_PRESENT)
+		sfp_sm_event(sfp, SFP_E_INSERT);
+}
+
+static void sfp_detach(struct sfp *sfp)
+{
+	sfp->attached = false;
+	sfp_sm_event(sfp, SFP_E_REMOVE);
+}
+
 static void sfp_start(struct sfp *sfp)
 {
 	sfp_sm_event(sfp, SFP_E_DEV_UP);
@@ -687,6 +701,8 @@ static int sfp_module_eeprom(struct sfp *sfp, struct ethtool_eeprom *ee,
 }
 
 static const struct sfp_socket_ops sfp_module_ops = {
+	.attach = sfp_attach,
+	.detach = sfp_detach,
 	.start = sfp_start,
 	.stop = sfp_stop,
 	.module_info = sfp_module_info,
@@ -829,10 +845,6 @@ static int sfp_probe(struct platform_device *pdev)
 		sfp->set_state = sfp_gpio_set_state;
 	}
 
-	sfp->sfp_bus = sfp_register_socket(sfp->dev, sfp, &sfp_module_ops);
-	if (!sfp->sfp_bus)
-		return -ENOMEM;
-
 	/* Get the initial state, and always signal TX disable,
 	 * since the network interface will not be up.
 	 */
@@ -843,10 +855,6 @@ static int sfp_probe(struct platform_device *pdev)
 		sfp->state |= SFP_F_RATE_SELECT;
 	sfp_set_state(sfp, sfp->state);
 	sfp_module_tx_disable(sfp);
-	rtnl_lock();
-	if (sfp->state & SFP_F_PRESENT)
-		sfp_sm_event(sfp, SFP_E_INSERT);
-	rtnl_unlock();
 
 	for (i = 0; i < GPIO_MAX; i++) {
 		if (gpio_flags[i] != GPIOD_IN || !sfp->gpio[i])
@@ -879,6 +887,10 @@ static int sfp_remove(struct platform_device *pdev)
 
 	sfp_unregister_socket(sfp->sfp_bus);
 
+	sfp->sfp_bus = sfp_register_socket(sfp->dev, sfp, &sfp_module_ops);
+	if (!sfp->sfp_bus)
+		return -ENOMEM;
+
 	return 0;
 }
 
diff --git a/drivers/net/phy/sfp.h b/drivers/net/phy/sfp.h
index 31b0acf337e27..64f54b0bbd8c4 100644
--- a/drivers/net/phy/sfp.h
+++ b/drivers/net/phy/sfp.h
@@ -7,6 +7,8 @@
 struct sfp;
 
 struct sfp_socket_ops {
+	void (*attach)(struct sfp *sfp);
+	void (*detach)(struct sfp *sfp);
 	void (*start)(struct sfp *sfp);
 	void (*stop)(struct sfp *sfp);
 	int (*module_info)(struct sfp *sfp, struct ethtool_modinfo *modinfo);