[PATCH 04/26] usb: gadget: introduce 'enabled' flag in struct usb_ep

[Robert Baldyga]

This patch introduces 'enabled' flag in struct usb_ep, and modifies
usb_ep_enable() and usb_ep_disable() functions to encapsulate endpoint
enabled/disabled state. It helps to avoid enabling endpoints which are
already enabled, and disabling endpoints which are already disables.

>From now USB functions don't have to remember current endpoint
enable/disable state, as this state is now handled automatically which
makes this API less bug-prone.

Signed-off-by: Robert Baldyga <r.bald...@samsung.com>
---
 include/linux/usb/gadget.h | 21 +++++++++++++++++++--
 1 file changed, 19 insertions(+), 2 deletions(-)

diff --git a/include/linux/usb/gadget.h b/include/linux/usb/gadget.h
index 3f299e2..63375cd 100644
--- a/include/linux/usb/gadget.h
+++ b/include/linux/usb/gadget.h
@@ -215,6 +215,7 @@ struct usb_ep {
        struct list_head        ep_list;
        struct usb_ep_caps      caps;
        bool                    claimed;
+       bool                    enabled;
        unsigned                maxpacket:16;
        unsigned                maxpacket_limit:16;
        unsigned                max_streams:16;
@@ -264,7 +265,15 @@ static inline void usb_ep_set_maxpacket_limit(struct 
usb_ep *ep,
  */
 static inline int usb_ep_enable(struct usb_ep *ep)
 {
-       return ep->ops->enable(ep, ep->desc);
+       int ret = 0;
+
+       if (!ep->enabled) {
+               ret = ep->ops->enable(ep, ep->desc);
+               if (!ret)
+                       ep->enabled = true;
+       }
+
+       return ret;
 }
 
 /**
@@ -281,7 +290,15 @@ static inline int usb_ep_enable(struct usb_ep *ep)
  */
 static inline int usb_ep_disable(struct usb_ep *ep)
 {
-       return ep->ops->disable(ep);
+       int ret = 0;
+
+       if (ep->enabled) {
+               ret = ep->ops->disable(ep);
+               if (!ret)
+                       ep->enabled = false;
+       }
+
+       return ret;
 }
 
 /**
-- 
1.9.1

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