patch "usb: f_fs: Prevent gadget unbind if it is already unbound" added to usb-next

This is a note to let you know that I've just added the patch titled

usb: f_fs: Prevent gadget unbind if it is already unbound

to my usb git tree which can be found at
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git
in the usb-next branch.

The patch will show up in the next release of the linux-next tree (usually sometime within the next 24 hours during the week.)

The patch will also be merged in the next major kernel release during the merge window.

If you have any questions about this process, please let me know.

From: Hemant Kumar <[email protected]>
Date: Tue, 9 Jan 2018 12:30:53 +0530
Subject: usb: f_fs: Prevent gadget unbind if it is already unbound

Upon usb composition switch there is possibility of ep0 file release happening after gadget driver bind. In case of composition switch from adb to a non-adb composition gadget will never gets bound again resulting into failure of usb device enumeration. Fix this issue by checking FFS_FL_BOUND flag and avoid extra gadget driver unbind if it is already done as part of composition switch.

This fixes adb reconnection error reported on Android running v4.4 and above kernel versions. Verified on Hikey running vanilla v4.15-rc7 + few out of tree Mali patches.

Reviewed-at: https://android-review.googlesource.com/#/c/582632/

---
 drivers/usb/gadget/function/f_fs.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

index 038a27a13ebc..686af89323a5 100644
@@ -3703,7 +3703,8 @@ static void ffs_closed(struct ffs_data *ffs)
 	ci = opts->func_inst.group.cg_item.ci_parent->ci_parent;
 	ffs_dev_unlock();
 
-	unregister_gadget_item(ci);
+	if (test_bit(FFS_FL_BOUND, &ffs->flags))
+		unregister_gadget_item(ci);
 	return;
 done:
 	ffs_dev_unlock();

2.15.1