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Commit 222155de authored by Jerry Zhang's avatar Jerry Zhang Committed by Felipe Balbi
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usb: gadget: function: f_fs: Let ffs_epfile_ioctl wait for enable. 



This allows users to make an ioctl call as the first action on a
connection. Ex, some functions might want to get endpoint size
before making any i/os.

Previously, calling ioctls before read/write would depending on the
timing of endpoints being enabled.

ESHUTDOWN is now a possible return value and ENODEV is not, so change
docs accordingly.

Acked-by: default avatarMichal Nazarewicz <mina86@mina86.com>
Signed-off-by: default avatarJerry Zhang <zhangjerry@google.com>
Signed-off-by: default avatarFelipe Balbi <felipe.balbi@linux.intel.com>
parent 8a8b161d

drivers/usb/gadget/function/f_fs.c

+54 −39
Original line number Diff line number Diff line
@@ -1189,6 +1189,7 @@ static long ffs_epfile_ioctl(struct file *file, unsigned code, 
			     unsigned long value)

{

	struct ffs_epfile *epfile = file->private_data;

	struct ffs_ep *ep;

	int ret;



	ENTER();
@@ -1196,8 +1197,25 @@ static long ffs_epfile_ioctl(struct file *file, unsigned code, 
	if (WARN_ON(epfile->ffs->state != FFS_ACTIVE))

		return -ENODEV;



	/* Wait for endpoint to be enabled */

	ep = epfile->ep;

	if (!ep) {

		if (file->f_flags & O_NONBLOCK)

			return -EAGAIN;



		ret = wait_event_interruptible(epfile->wait, (ep = epfile->ep));

		if (ret)

			return -EINTR;

	}



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

	if (likely(epfile->ep)) {



	/* In the meantime, endpoint got disabled or changed. */

	if (epfile->ep != ep) {

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

		return -ESHUTDOWN;

	}



	switch (code) {

	case FUNCTIONFS_FIFO_STATUS:

		ret = usb_ep_fifo_status(epfile->ep->ep);
@@ -1238,9 +1256,6 @@ static long ffs_epfile_ioctl(struct file *file, unsigned code, 
	default:

		ret = -ENOTTY;

	}

	} else {

		ret = -ENODEV;

	}

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



	return ret;

include/uapi/linux/usb/functionfs.h

+4 −3
Original line number Diff line number Diff line
@@ -275,13 +275,14 @@ struct usb_functionfs_event { 
#define	FUNCTIONFS_INTERFACE_REVMAP	_IO('g', 128)



/*

 * Returns real bEndpointAddress of an endpoint.  If function is not

 * active returns -ENODEV.

 * Returns real bEndpointAddress of an endpoint. If endpoint shuts down

 * during the call, returns -ESHUTDOWN.

 */

#define	FUNCTIONFS_ENDPOINT_REVMAP	_IO('g', 129)



/*

 * Returns endpoint descriptor. If function is not active returns -ENODEV.

 * Returns endpoint descriptor. If endpoint shuts down during the call,

 * returns -ESHUTDOWN.

 */

#define	FUNCTIONFS_ENDPOINT_DESC	_IOR('g', 130, \

					     struct usb_endpoint_descriptor)