usb: gadget: functionfs: replace FFS_SETUP_STATUS with an inline function

The FFS_SETUP_STATUS macro could be trivialy replaced with an static
inline function but more importantly its name was tad confusing.
The name suggested it was a simple accessor macro but it actually
did change the state of the ffs_data structure perfomring
a FFS_SETUP_CANCELLED -> FFS_NO_SETUP transition.  The name of the
function -- ffs_setup_state_clear_cancelled -- should better
describe what the function actually does.
Signed-off-by: Michal Nazarewicz <mina86@mina86.com>
Signed-off-by: Robert Baldyga <r.baldyga@samsung.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>

drivers/usb/gadget/f_fs.c

@@ -99,6 +99,14 @@ static struct ffs_function *ffs_func_from_usb(struct usb_function *f)
 }
 
 
+static inline enum ffs_setup_state
+ffs_setup_state_clear_cancelled(struct ffs_data *ffs)
+{
+	return (enum ffs_setup_state)
+		cmpxchg(&ffs->setup_state, FFS_SETUP_CANCELLED, FFS_NO_SETUP);
+}
+
+
 static void ffs_func_eps_disable(struct ffs_function *func);
 static int __must_check ffs_func_eps_enable(struct ffs_function *func);
 
@@ -246,7 +254,7 @@ static ssize_t ffs_ep0_write(struct file *file, const char __user *buf,
 	ENTER();
 
 	/* Fast check if setup was canceled */
-	if (FFS_SETUP_STATE(ffs) == FFS_SETUP_CANCELLED)
+	if (ffs_setup_state_clear_cancelled(ffs) == FFS_SETUP_CANCELLED)
 		return -EIDRM;
 
 	/* Acquire mutex */
@@ -312,7 +320,7 @@ static ssize_t ffs_ep0_write(struct file *file, const char __user *buf,
 		 * rather then _irqsave
 		 */
 		spin_lock_irq(&ffs->ev.waitq.lock);
-		switch (FFS_SETUP_STATE(ffs)) {
+		switch (ffs_setup_state_clear_cancelled(ffs)) {
 		case FFS_SETUP_CANCELLED:
 			ret = -EIDRM;
 			goto done_spin;
@@ -357,7 +365,8 @@ static ssize_t ffs_ep0_write(struct file *file, const char __user *buf,
 		 * transition can be performed and it's protected by
 		 * mutex.
 		 */
-		if (FFS_SETUP_STATE(ffs) == FFS_SETUP_CANCELLED) {
+		if (ffs_setup_state_clear_cancelled(ffs) ==
+		    FFS_SETUP_CANCELLED) {
 			ret = -EIDRM;
 done_spin:
 			spin_unlock_irq(&ffs->ev.waitq.lock);
@@ -423,7 +432,7 @@ static ssize_t ffs_ep0_read(struct file *file, char __user *buf,
 	ENTER();
 
 	/* Fast check if setup was canceled */
-	if (FFS_SETUP_STATE(ffs) == FFS_SETUP_CANCELLED)
+	if (ffs_setup_state_clear_cancelled(ffs) == FFS_SETUP_CANCELLED)
 		return -EIDRM;
 
 	/* Acquire mutex */
@@ -443,7 +452,7 @@ static ssize_t ffs_ep0_read(struct file *file, char __user *buf,
 	 */
 	spin_lock_irq(&ffs->ev.waitq.lock);
 
-	switch (FFS_SETUP_STATE(ffs)) {
+	switch (ffs_setup_state_clear_cancelled(ffs)) {
 	case FFS_SETUP_CANCELLED:
 		ret = -EIDRM;
 		break;
@@ -491,7 +500,8 @@ static ssize_t ffs_ep0_read(struct file *file, char __user *buf,
 		spin_lock_irq(&ffs->ev.waitq.lock);
 
 		/* See ffs_ep0_write() */
-		if (FFS_SETUP_STATE(ffs) == FFS_SETUP_CANCELLED) {
+		if (ffs_setup_state_clear_cancelled(ffs) ==
+		    FFS_SETUP_CANCELLED) {
 			ret = -EIDRM;
 			break;
 		}

drivers/usb/gadget/u_fs.h

@@ -172,13 +172,12 @@ struct ffs_data {
 	 *               happens only in ep0 i/o  which is P: mutex
 	 * + FFS_SETUP_PENDING   -> FFS_SETUP_CANCELLED -- P: ev.waitq.lock
 	 * + FFS_SETUP_CANCELLED -> FFS_NO_SETUP        -- cmpxchg
+	 *
+	 * This field should never be accessed directly and instead
+	 * ffs_setup_state_clear_cancelled function should be used.
 	 */
 	enum ffs_setup_state		setup_state;
 
-#define FFS_SETUP_STATE(ffs)					\
-	((enum ffs_setup_state)cmpxchg(&(ffs)->setup_state,	\
-				       FFS_SETUP_CANCELLED, FFS_NO_SETUP))
-
 	/* Events & such. */
 	struct {
 		u8				types[4];