usb: gadget: f_fs: Fix iterations on endpoints.

When zero endpoints are declared for a function, there is no endpoint
to disable, enable or free, so replace do...while loops with while loops.
Change pre-decrement to post-decrement to iterate the same number of times
when there are endpoints to process.

Signed-off-by: Vincent Pelletier <plr.vincent@gmail.com>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>

diff --git a/drivers/usb/gadget/function/f_fs.c b/drivers/usb/gadget/function/f_fs.c
index 5e746ad..5490fc5 100644 (file)
--- a/drivers/usb/gadget/function/f_fs.c
+++ b/drivers/usb/gadget/function/f_fs.c
@@ -1806,7 +1806,7 @@ static void ffs_func_eps_disable(struct ffs_function *func)
        unsigned long flags;
 
        spin_lock_irqsave(&func->ffs->eps_lock, flags);
-       do {
+       while (count--) {
                /* pending requests get nuked */
                if (likely(ep->ep))
                        usb_ep_disable(ep->ep);
@@ -1817,7 +1817,7 @@ static void ffs_func_eps_disable(struct ffs_function *func)
                        __ffs_epfile_read_buffer_free(epfile);
                        ++epfile;
                }
-       } while (--count);
+       }
        spin_unlock_irqrestore(&func->ffs->eps_lock, flags);
 }
 
@@ -1831,7 +1831,7 @@ static int ffs_func_eps_enable(struct ffs_function *func)
        int ret = 0;
 
        spin_lock_irqsave(&func->ffs->eps_lock, flags);
-       do {
+       while(count--) {
                struct usb_endpoint_descriptor *ds;
                int desc_idx;
 
@@ -1867,7 +1867,7 @@ static int ffs_func_eps_enable(struct ffs_function *func)
 
                ++ep;
                ++epfile;
-       } while (--count);
+       }
        spin_unlock_irqrestore(&func->ffs->eps_lock, flags);
 
        return ret;
@@ -3448,12 +3448,12 @@ static void ffs_func_unbind(struct usb_configuration *c,
 
        /* cleanup after autoconfig */
        spin_lock_irqsave(&func->ffs->eps_lock, flags);
-       do {
+       while (count--) {
                if (ep->ep && ep->req)
                        usb_ep_free_request(ep->ep, ep->req);
                ep->req = NULL;
                ++ep;
-       } while (--count);
+       }
        spin_unlock_irqrestore(&func->ffs->eps_lock, flags);
        kfree(func->eps);
        func->eps = NULL;