Commit b447e287 authored Jun 03, 2020 by Udipto Goswami

USB: f_mtp: Revert Avoid queuing of receive_file_work for 0 length



Commit 76f7005a ("USB: f_mtp: Avoid queuing of receive_file_work
for 0 length") adds a check for 0 length file and avoid queuing in
order to save some milliseconds in mtp file transfers.
However, this approach is correct only for windows system as it
ignores 0 length files but other OS like MAC & Ubuntu do not follow
this logic. They allows 0 length file to be copied which is why mtp
file transfer failure is observed when target is connected to MAC
or Ubuntu.

Fix this by reverting the check for 0 length.

Change-Id: I48559e89afa7a4220bdef3f078e2aa739c402b4b
Signed-off-by: Udipto Goswami <ugoswami@codeaurora.org>

parent 757f1d14

drivers/usb/gadget/function/f_mtp.c

+7 −10

Original line number	Diff line number	Diff line
		@@ -1128,17 +1128,14 @@ static long mtp_send_receive_ioctl(struct file *fp, unsigned int code,
		* in kernel context, which is necessary for vfs_read and
		* vfs_write to use our buffers in the kernel address space.
		*/
		dev->xfer_result = 0;
		if (dev->xfer_file_length) {
		queue_work(dev->wq, work);
		/* wait for operation to complete */
		flush_workqueue(dev->wq);
		fput(filp);

		/* read the result */
		smp_rmb();
		}
		ret = dev->xfer_result;
		fput(filp);

		fail:
		spin_lock_irq(&dev->lock);