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 ce5bf9a50daf2d9078b505aca1cea22e88ecb94a Mon Sep 17 00:00:00 2001 From: Hemant Kumar <hemantk@xxxxxxxxxxxxxx> 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/ Cc: Felipe Balbi <balbi@xxxxxxxxxx> Cc: Greg KH <gregkh@xxxxxxxxxxxxxxxxxxxx> Cc: Michal Nazarewicz <mina86@xxxxxxxxxx> Cc: John Stultz <john.stultz@xxxxxxxxxx> Cc: Dmitry Shmidt <dimitrysh@xxxxxxxxxx> Cc: Badhri <badhri@xxxxxxxxxx> Cc: Android Kernel Team <kernel-team@xxxxxxxxxxx> Cc: stable@xxxxxxxxxxxxxxx Signed-off-by: Hemant Kumar <hemantk@xxxxxxxxxxxxxx> [AmitP: Cherry-picked it from android-4.14 and updated the commit log] Signed-off-by: Amit Pundir <amit.pundir@xxxxxxxxxx> Cc: stable <stable@xxxxxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/usb/gadget/function/f_fs.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/usb/gadget/function/f_fs.c b/drivers/usb/gadget/function/f_fs.c index 038a27a13ebc..686af89323a5 100644 --- a/drivers/usb/gadget/function/f_fs.c +++ b/drivers/usb/gadget/function/f_fs.c @@ -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