USB: gadgetfs cleanups

Minor gadgetfs cleanups:

 - EP0 state constants become consistently STATE_DEV_* rather than
   sometimes omitting the "DEV_"; STATE_EP_* were already consistent.

 - Comment that ep0 state is protected by the spinlock, and update
   code that was neglecting that rule.

None of this is expected to change behavior.

Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

1 files changed, 41 insertions, 34 deletions

diff --git a/drivers/usb/gadget/inode.c b/drivers/usb/gadget/inode.c
index 0f00249720b..cbdcb3c10c5 100644
--- a/drivers/usb/gadget/inode.c
+++ b/drivers/usb/gadget/inode.c
@@ -98,16 +98,16 @@ enum ep0_state {
          * must always write descriptors to initialize the device, then
          * the device becomes UNCONNECTED until enumeration.
          */
-        STATE_OPENED,
+        STATE_DEV_OPENED,
 
         /* From then on, ep0 fd is in either of two basic modes:
          * - (UN)CONNECTED: read usb_gadgetfs_event(s) from it
          * - SETUP: read/write will transfer control data and succeed;
          *   or if "wrong direction", performs protocol stall
          */
-        STATE_UNCONNECTED,
-        STATE_CONNECTED,
-        STATE_SETUP,
+        STATE_DEV_UNCONNECTED,
+        STATE_DEV_CONNECTED,
+        STATE_DEV_SETUP,
 
         /* UNBOUND means the driver closed ep0, so the device won't be
          * accessible again (DEV_DISABLED) until all fds are closed.
@@ -121,7 +121,7 @@ enum ep0_state {
 struct dev_data {
         spinlock_t                      lock;
         atomic_t                        count;
-        enum ep0_state                  state;
+        enum ep0_state                  state;          /* P: lock */
         struct usb_gadgetfs_event       event [N_EVENT];
         unsigned                        ev_next;
         struct fasync_struct            *fasync;
@@ -942,8 +942,14 @@ static void ep0_complete (struct usb_ep *ep, struct usb_request *req)
                         free = 0;
                 dev->setup_out_ready = 1;
                 ep0_readable (dev);
-        } else if (dev->state == STATE_SETUP)
-                dev->state = STATE_CONNECTED;
+        } else {
+                unsigned long   flags;
+
+                spin_lock_irqsave(&dev->lock, flags);
+                if (dev->state == STATE_DEV_SETUP)
+                        dev->state = STATE_DEV_CONNECTED;
+                spin_unlock_irqrestore(&dev->lock, flags);
+        }
 
         /* clean up as appropriate */
         if (free && req->buf != &dev->rbuf)
@@ -988,13 +994,13 @@ ep0_read (struct file *fd, char __user *buf, size_t len, loff_t *ptr)
         }
 
         /* control DATA stage */
-        if ((state = dev->state) == STATE_SETUP) {
+        if ((state = dev->state) == STATE_DEV_SETUP) {
 
                 if (dev->setup_in) {            /* stall IN */
                         VDEBUG(dev, "ep0in stall\n");
                         (void) usb_ep_set_halt (dev->gadget->ep0);
                         retval = -EL2HLT;
-                        dev->state = STATE_CONNECTED;
+                        dev->state = STATE_DEV_CONNECTED;
 
                 } else if (len == 0) {          /* ack SET_CONFIGURATION etc */
                         struct usb_ep           *ep = dev->gadget->ep0;
@@ -1002,7 +1008,7 @@ ep0_read (struct file *fd, char __user *buf, size_t len, loff_t *ptr)
 
                         if ((retval = setup_req (ep, req, 0)) == 0)
                                 retval = usb_ep_queue (ep, req, GFP_ATOMIC);
-                        dev->state = STATE_CONNECTED;
+                        dev->state = STATE_DEV_CONNECTED;
 
                         /* assume that was SET_CONFIGURATION */
                         if (dev->current_config) {
@@ -1061,7 +1067,7 @@ scan:
                 len = min (len, tmp * sizeof (struct usb_gadgetfs_event));
                 n = len / sizeof (struct usb_gadgetfs_event);
 
-                /* ep0 can't deliver events when STATE_SETUP */
+                /* ep0 can't deliver events when STATE_DEV_SETUP */
                 for (i = 0; i < n; i++) {
                         if (dev->event [i].type == GADGETFS_SETUP) {
                                 len = i + 1;
@@ -1088,7 +1094,7 @@ scan:
                                         sizeof (struct usb_gadgetfs_event)
                                                 * (tmp - len));
                         if (n == 0)
-                                dev->state = STATE_SETUP;
+                                dev->state = STATE_DEV_SETUP;
                         spin_unlock_irq (&dev->lock);
                 }
                 return retval;
@@ -1103,8 +1109,8 @@ scan:
                 DBG (dev, "fail %s, state %d\n", __FUNCTION__, state);
                 retval = -ESRCH;
                 break;
-        case STATE_UNCONNECTED:
-        case STATE_CONNECTED:
+        case STATE_DEV_UNCONNECTED:
+        case STATE_DEV_CONNECTED:
                 spin_unlock_irq (&dev->lock);
                 DBG (dev, "%s wait\n", __FUNCTION__);
 
@@ -1131,7 +1137,7 @@ next_event (struct dev_data *dev, enum usb_gadgetfs_event_type type)
         switch (type) {
         /* these events purge the queue */
         case GADGETFS_DISCONNECT:
-                if (dev->state == STATE_SETUP)
+                if (dev->state == STATE_DEV_SETUP)
                         dev->setup_abort = 1;
                 // FALL THROUGH
         case GADGETFS_CONNECT:
@@ -1178,7 +1184,7 @@ ep0_write (struct file *fd, const char __user *buf, size_t len, loff_t *ptr)
                 retval = -EIDRM;
 
         /* data and/or status stage for control request */
-        } else if (dev->state == STATE_SETUP) {
+        } else if (dev->state == STATE_DEV_SETUP) {
 
                 /* IN DATA+STATUS caller makes len <= wLength */
                 if (dev->setup_in) {
@@ -1209,7 +1215,7 @@ ep0_write (struct file *fd, const char __user *buf, size_t len, loff_t *ptr)
                         VDEBUG(dev, "ep0out stall\n");
                         (void) usb_ep_set_halt (dev->gadget->ep0);
                         retval = -EL2HLT;
-                        dev->state = STATE_CONNECTED;
+                        dev->state = STATE_DEV_CONNECTED;
                 } else {
                         DBG(dev, "bogus ep0out stall!\n");
                 }
@@ -1251,7 +1257,9 @@ dev_release (struct inode *inode, struct file *fd)
         put_dev (dev);
 
         /* other endpoints were all decoupled from this device */
+        spin_lock_irq(&dev->lock);
         dev->state = STATE_DEV_DISABLED;
+        spin_unlock_irq(&dev->lock);
         return 0;
 }
 
@@ -1272,7 +1280,7 @@ ep0_poll (struct file *fd, poll_table *wait)
                goto out;
        }
 
-       if (dev->state == STATE_SETUP) {
+       if (dev->state == STATE_DEV_SETUP) {
                if (dev->setup_in || dev->setup_can_stall)
                        mask = POLLOUT;
        } else {
@@ -1382,9 +1390,9 @@ gadgetfs_setup (struct usb_gadget *gadget, const struct usb_ctrlrequest *ctrl)
 
         spin_lock (&dev->lock);
         dev->setup_abort = 0;
-        if (dev->state == STATE_UNCONNECTED) {
+        if (dev->state == STATE_DEV_UNCONNECTED) {
 
-                dev->state = STATE_CONNECTED;
+                dev->state = STATE_DEV_CONNECTED;
                 dev->dev->bMaxPacketSize0 = gadget->ep0->maxpacket;
 
 #ifdef  CONFIG_USB_GADGET_DUALSPEED
@@ -1404,7 +1412,7 @@ gadgetfs_setup (struct usb_gadget *gadget, const struct usb_ctrlrequest *ctrl)
          * then ep0_{read,write} will report the wrong status. controller
          * driver will have aborted pending i/o.
          */
-        } else if (dev->state == STATE_SETUP)
+        } else if (dev->state == STATE_DEV_SETUP)
                 dev->setup_abort = 1;
 
         req->buf = dev->rbuf;
@@ -1550,7 +1558,7 @@ delegate:
         }
 
         /* proceed with data transfer and status phases? */
-        if (value >= 0 && dev->state != STATE_SETUP) {
+        if (value >= 0 && dev->state != STATE_DEV_SETUP) {
                 req->length = value;
                 req->zero = value < w_length;
                 value = usb_ep_queue (gadget->ep0, req, GFP_ATOMIC);
@@ -1714,7 +1722,9 @@ gadgetfs_bind (struct usb_gadget *gadget)
                 goto enomem;
 
         INFO (dev, "bound to %s driver\n", gadget->name);
-        dev->state = STATE_UNCONNECTED;
+        spin_lock_irq(&dev->lock);
+        dev->state = STATE_DEV_UNCONNECTED;
+        spin_unlock_irq(&dev->lock);
         get_dev (dev);
         return 0;
 
@@ -1729,11 +1739,9 @@ gadgetfs_disconnect (struct usb_gadget *gadget)
         struct dev_data         *dev = get_gadget_data (gadget);
 
         spin_lock (&dev->lock);
-        if (dev->state == STATE_UNCONNECTED) {
-                DBG (dev, "already unconnected\n");
+        if (dev->state == STATE_DEV_UNCONNECTED)
                 goto exit;
-        }
-        dev->state = STATE_UNCONNECTED;
+        dev->state = STATE_DEV_UNCONNECTED;
 
         INFO (dev, "disconnected\n");
         next_event (dev, GADGETFS_DISCONNECT);
@@ -1750,9 +1758,9 @@ gadgetfs_suspend (struct usb_gadget *gadget)
         INFO (dev, "suspended from state %d\n", dev->state);
         spin_lock (&dev->lock);
         switch (dev->state) {
-        case STATE_SETUP:               // VERY odd... host died??
-        case STATE_CONNECTED:
-        case STATE_UNCONNECTED:
+        case STATE_DEV_SETUP:           // VERY odd... host died??
+        case STATE_DEV_CONNECTED:
+        case STATE_DEV_UNCONNECTED:
                 next_event (dev, GADGETFS_SUSPEND);
                 ep0_readable (dev);
                 /* FALLTHROUGH */
@@ -1848,9 +1856,6 @@ dev_config (struct file *fd, const char __user *buf, size_t len, loff_t *ptr)
         u32                     tag;
         char                    *kbuf;
 
-        if (dev->state != STATE_OPENED)
-                return -EEXIST;
-
         if (len < (USB_DT_CONFIG_SIZE + USB_DT_DEVICE_SIZE + 4))
                 return -EINVAL;
 
@@ -1942,13 +1947,15 @@ dev_open (struct inode *inode, struct file *fd)
         struct dev_data         *dev = inode->i_private;
         int                     value = -EBUSY;
 
+        spin_lock_irq(&dev->lock);
         if (dev->state == STATE_DEV_DISABLED) {
                 dev->ev_next = 0;
-                dev->state = STATE_OPENED;
+                dev->state = STATE_DEV_OPENED;
                 fd->private_data = dev;
                 get_dev (dev);
                 value = 0;
         }
+        spin_unlock_irq(&dev->lock);
         return value;
 }