1 files changed, 51 insertions, 5 deletions

diff --git a/drivers/usb/gadget/function/f_fs.c b/drivers/usb/gadget/function/f_fs.c
index a00ee977305c..e78a2c6af8d3 100644
--- a/drivers/usb/gadget/function/f_fs.c
+++ b/drivers/usb/gadget/function/f_fs.c
@@ -605,6 +605,8 @@ static unsigned int ffs_ep0_poll(struct file *file, poll_table *wait)
 		}
 	case FFS_CLOSING:
 		break;
+	case FFS_DEACTIVATED:
+		break;
 	}
 
 	mutex_unlock(&ffs->mutex);
@@ -1179,6 +1181,7 @@ struct ffs_sb_fill_data {
 	struct ffs_file_perms perms;
 	umode_t root_mode;
 	const char *dev_name;
+	bool no_disconnect;
 	struct ffs_data *ffs_data;
 };
 
@@ -1249,6 +1252,12 @@ static int ffs_fs_parse_opts(struct ffs_sb_fill_data *data, char *opts)
 
 		/* Interpret option */
 		switch (eq - opts) {
+		case 13:
+			if (!memcmp(opts, "no_disconnect", 13))
+				data->no_disconnect = !!value;
+			else
+				goto invalid;
+			break;
 		case 5:
 			if (!memcmp(opts, "rmode", 5))
 				data->root_mode  = (value & 0555) | S_IFDIR;
@@ -1313,6 +1322,7 @@ ffs_fs_mount(struct file_system_type *t, int flags,
 			.gid = GLOBAL_ROOT_GID,
 		},
 		.root_mode = S_IFDIR | 0500,
+		.no_disconnect = false,
 	};
 	struct dentry *rv;
 	int ret;
@@ -1329,6 +1339,7 @@ ffs_fs_mount(struct file_system_type *t, int flags,
 	if (unlikely(!ffs))
 		return ERR_PTR(-ENOMEM);
 	ffs->file_perms = data.perms;
+	ffs->no_disconnect = data.no_disconnect;
 
 	ffs->dev_name = kstrdup(dev_name, GFP_KERNEL);
 	if (unlikely(!ffs->dev_name)) {
@@ -1360,6 +1371,7 @@ ffs_fs_kill_sb(struct super_block *sb)
 	kill_litter_super(sb);
 	if (sb->s_fs_info) {
 		ffs_release_dev(sb->s_fs_info);
+		ffs_data_closed(sb->s_fs_info);
 		ffs_data_put(sb->s_fs_info);
 	}
 }
@@ -1416,7 +1428,11 @@ static void ffs_data_opened(struct ffs_data *ffs)
 	ENTER();
 
 	atomic_inc(&ffs->ref);
-	atomic_inc(&ffs->opened);
+	if (atomic_add_return(1, &ffs->opened) == 1 &&
+			ffs->state == FFS_DEACTIVATED) {
+		ffs->state = FFS_CLOSING;
+		ffs_data_reset(ffs);
+	}
 }
 
 static void ffs_data_put(struct ffs_data *ffs)
@@ -1438,6 +1454,21 @@ static void ffs_data_closed(struct ffs_data *ffs)
 	ENTER();
 
 	if (atomic_dec_and_test(&ffs->opened)) {
+		if (ffs->no_disconnect) {
+			ffs->state = FFS_DEACTIVATED;
+			if (ffs->epfiles) {
+				ffs_epfiles_destroy(ffs->epfiles,
+						   ffs->eps_count);
+				ffs->epfiles = NULL;
+			}
+			if (ffs->setup_state == FFS_SETUP_PENDING)
+				__ffs_ep0_stall(ffs);
+		} else {
+			ffs->state = FFS_CLOSING;
+			ffs_data_reset(ffs);
+		}
+	}
+	if (atomic_read(&ffs->opened) < 0) {
 		ffs->state = FFS_CLOSING;
 		ffs_data_reset(ffs);
 	}
@@ -1615,7 +1646,6 @@ static void ffs_epfiles_destroy(struct ffs_epfile *epfiles, unsigned count)
 	kfree(epfiles);
 }
 
-
 static void ffs_func_eps_disable(struct ffs_function *func)
 {
 	struct ffs_ep *ep         = func->eps;
@@ -1628,10 +1658,12 @@ static void ffs_func_eps_disable(struct ffs_function *func)
 		/* pending requests get nuked */
 		if (likely(ep->ep))
 			usb_ep_disable(ep->ep);
-		epfile->ep = NULL;
-
 		++ep;
-		++epfile;
+
+		if (epfile) {
+			epfile->ep = NULL;
+			++epfile;
+		}
 	} while (--count);
 	spin_unlock_irqrestore(&func->ffs->eps_lock, flags);
 }
@@ -2894,6 +2926,13 @@ static int ffs_func_bind(struct usb_configuration *c,
 
 /* Other USB function hooks *************************************************/
 
+static void ffs_reset_work(struct work_struct *work)
+{
+	struct ffs_data *ffs = container_of(work,
+		struct ffs_data, reset_work);
+	ffs_data_reset(ffs);
+}
+
 static int ffs_func_set_alt(struct usb_function *f,
 			    unsigned interface, unsigned alt)
 {
@@ -2910,6 +2949,13 @@ static int ffs_func_set_alt(struct usb_function *f,
 	if (ffs->func)
 		ffs_func_eps_disable(ffs->func);
 
+	if (ffs->state == FFS_DEACTIVATED) {
+		ffs->state = FFS_CLOSING;
+		INIT_WORK(&ffs->reset_work, ffs_reset_work);
+		schedule_work(&ffs->reset_work);
+		return -ENODEV;
+	}
+
 	if (ffs->state != FFS_ACTIVE)
 		return -ENODEV;