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Commit ea6ae44c authored by Mayank Rana's avatar Mayank Rana
Browse files

USB: f_fs: Allow epfile to be opened only once 



Due to USB cable disconnect, ADBD closes its epfiles and re-opens the same.
In normal operation the sequence is:
ffs_func_eps_disable() setting epfile->error to 1
ffs_epfile_release() setting epfile->error to 1
ffs_epfile_open() setting epfile->error to 0
In some cases when above sequeunce gets changed, epfile->error is set to 1.
Hence there is no data transfer happening on ep-IN endpoint. Fix this by
not allowing opening of epfiles until it has being successfully released.

CRs-Fixed: 881892
Change-Id: I26b9ec1b6218d00cc0965ce3e71fcea49f9bf567
Signed-off-by: default avatarMayank Rana <mrana@codeaurora.org>
parent bccaa565

drivers/usb/gadget/function/f_fs.c

+12 −0
Original line number Diff line number Diff line
@@ -209,6 +209,7 @@ struct ffs_epfile { 
	unsigned char			isoc;	/* P: ffs->eps_lock */



	unsigned char			_pad;

	atomic_t			opened;

};



struct ffs_buffer {
@@ -1206,6 +1207,15 @@ ffs_epfile_open(struct inode *inode, struct file *file) 
	if (WARN_ON(epfile->ffs->state != FFS_ACTIVE))

		return -ENODEV;



	/* to get updated opened atomic variable value */

	smp_mb__before_atomic();

	if (atomic_read(&epfile->opened)) {

		pr_err("%s(): ep(%s) is already opened.\n",

					__func__, epfile->name);

		return -EBUSY;

	}



	atomic_set(&epfile->opened, 1);

	file->private_data = epfile;

	ffs_data_opened(epfile->ffs);

	atomic_set(&epfile->error, 0);
@@ -1342,6 +1352,7 @@ ffs_epfile_release(struct inode *inode, struct file *file) 


	ENTER();



	atomic_set(&epfile->opened, 0);

	__ffs_epfile_read_buffer_free(epfile);

	ffs_log("enter:state %d setup_state %d flag %lu", epfile->ffs->state,

		epfile->ffs->setup_state, epfile->ffs->flags);
@@ -2027,6 +2038,7 @@ static int ffs_epfiles_create(struct ffs_data *ffs) 
		epfile->ffs = ffs;

		mutex_init(&epfile->mutex);

		init_waitqueue_head(&epfile->wait);

		atomic_set(&epfile->opened, 0);

		if (ffs->user_flags & FUNCTIONFS_VIRTUAL_ADDR)

			sprintf(epfile->name, "ep%02x", ffs->eps_addrmap[i]);

		else