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Commit ade2576e authored by Ajay Agarwal's avatar Ajay Agarwal
Browse files

USB: gadget: ffs: Fix USBCV compliance failure due to adbd 



Userspace f_fs client e.g. ADB daemon can re-open ep0 file node
on adb_read/write error (or on bus reset). This results in device
disabling and enabling pull-up on bus reset. USBCV CH9 tests which
perform bus resets also fail due to this.
Fix this by not failing adb_read on bus reset so that adbd client
woudln't attempt ep0-file close. This behavior is not changed for
composition switch or cable disconnect by checking if adb_read
was attempting first transfer after online state or it was in middle
of a session when disconnect happened.

Change-Id: I2378f22995b7ddffb17d618df059d8aedb594d97
Signed-off-by: default avatarAjay Agarwal <ajaya@codeaurora.org>
parent a3851309

drivers/usb/gadget/function/f_fs.c

+32 −2
Original line number Diff line number Diff line
@@ -71,6 +71,7 @@ __ffs_data_got_strings(struct ffs_data *ffs, char *data, size_t len); 
/* The function structure ***************************************************/



struct ffs_ep;

static bool first_read_done;



struct ffs_function {

	struct usb_configuration	*conf;
@@ -756,6 +757,7 @@ static ssize_t ffs_epfile_io(struct file *file, struct ffs_io_data *io_data) 
{

	struct ffs_epfile *epfile = file->private_data;

	struct ffs_ep *ep;

	struct ffs_data *ffs = epfile->ffs;

	char *data = NULL;

	ssize_t ret, data_len = -EINVAL;

	int halt;
@@ -764,6 +766,7 @@ static ssize_t ffs_epfile_io(struct file *file, struct ffs_io_data *io_data) 
		atomic_read(&epfile->error), io_data->read ? "READ" : "WRITE");



	smp_mb__before_atomic();

retry:

	if (atomic_read(&epfile->error))

		return -ENODEV;
@@ -968,10 +971,36 @@ static ssize_t ffs_epfile_io(struct file *file, struct ffs_io_data *io_data) 
				 * disabled (disconnect) or changed

				 * (composition switch) ?

				 */

				if (epfile->ep == ep)

				if (epfile->ep == ep) {

					ret = ep->status;

				else

					if (ret >= 0)

						first_read_done = true;

				} else {

					ret = -ENODEV;

				}



				/* do wait again if func eps are not enabled */

				if (io_data->read && !first_read_done

							&& ret < 0) {

					unsigned short count = ffs->eps_count;



					pr_debug("%s: waiting for the online state\n",

						 __func__);

					ret = 0;

					kfree(data);

					data = NULL;

					data_len = -EINVAL;

					spin_unlock_irq(&epfile->ffs->eps_lock);

					mutex_unlock(&epfile->mutex);

					epfile = ffs->epfiles;

					do {

						atomic_set(&epfile->error, 0);

						++epfile;

					} while (--count);

					epfile = file->private_data;

					goto retry;

				}



				spin_unlock_irq(&epfile->ffs->eps_lock);

				if (io_data->read && ret > 0) {
@@ -1038,6 +1067,7 @@ ffs_epfile_open(struct inode *inode, struct file *file) 


	smp_mb__before_atomic();

	atomic_set(&epfile->error, 0);

	first_read_done = false;



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

		epfile->ffs->setup_state, epfile->ffs->flags);