From: Johan Hovold <johan@hovoldconsulting.com>
Date: Wed, 20 Jul 2016 14:40:24 +0000 (+0200)
Subject: greybus: interface: prevent reactivation during removal
X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=12169bc9143ed24ad7a5ea12a7c28d1dba891131;p=linux-beck.git

greybus: interface: prevent reactivation during removal

Make sure to prevent an interface that is going away from being
reactivated.

This is needed to preemptively close a race between the upcoming feature
to reactivate a powered-down interface and physical removal (i.e.
module_removed event processing) as well as logical removal (e.g. the
current system-suspend hack).

Reviewed-by: Sandeep Patil <sspatil@google.com>
Signed-off-by: Johan Hovold <johan@hovoldconsulting.com>
Reviewed-by: Alex Elder <elder@linaro.org>
Reviewed-by: Viresh Kumar <viresh.kumar@linaro.org>
Reviewed-by: Patrick Titiano <ptitiano@baylibre.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
---

diff --git a/drivers/staging/greybus/interface.c b/drivers/staging/greybus/interface.c
index 01cefced7b69..3ad1c757d7e7 100644
--- a/drivers/staging/greybus/interface.c
+++ b/drivers/staging/greybus/interface.c
@@ -873,7 +873,7 @@ static int _gb_interface_activate(struct gb_interface *intf,
 
 	*type = GB_INTERFACE_TYPE_UNKNOWN;
 
-	if (intf->ejected)
+	if (intf->ejected || intf->removed)
 		return -ENODEV;
 
 	ret = gb_interface_vsys_set(intf, true);
diff --git a/drivers/staging/greybus/interface.h b/drivers/staging/greybus/interface.h
index f52dfd09bb16..daa9759149a5 100644
--- a/drivers/staging/greybus/interface.h
+++ b/drivers/staging/greybus/interface.h
@@ -53,6 +53,7 @@ struct gb_interface {
 	bool disconnected;
 
 	bool ejected;
+	bool removed;
 	bool active;
 	bool enabled;
 	bool mode_switch;
diff --git a/drivers/staging/greybus/module.c b/drivers/staging/greybus/module.c
index d506fa0b3272..69f67ddbd4a3 100644
--- a/drivers/staging/greybus/module.c
+++ b/drivers/staging/greybus/module.c
@@ -186,6 +186,7 @@ static void gb_module_deregister_interface(struct gb_interface *intf)
 		intf->disconnected = true;
 
 	mutex_lock(&intf->mutex);
+	intf->removed = true;
 	gb_interface_disable(intf);
 	gb_interface_deactivate(intf);
 	mutex_unlock(&intf->mutex);