2018-01-09 07:01:03

by Amit Pundir

[permalink] [raw]
Subject: [PATCH] usb: f_fs: Prevent gadget unbind if it is already unbound

From: Hemant Kumar <[email protected]>

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 <[email protected]>
Cc: Greg KH <[email protected]>
Cc: Michal Nazarewicz <[email protected]>
Cc: John Stultz <[email protected]>
Cc: Dmitry Shmidt <[email protected]>
Cc: Badhri <[email protected]>
Cc: Android Kernel Team <[email protected]>
Cc: [email protected]
Signed-off-by: Hemant Kumar <[email protected]>
[AmitP: Cherry-picked it from android-4.14 and updated the commit log]
Signed-off-by: Amit Pundir <[email protected]>
---
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 b6cf5ab5a0a1..f9bd351637cd 100644
--- a/drivers/usb/gadget/function/f_fs.c
+++ b/drivers/usb/gadget/function/f_fs.c
@@ -3700,7 +3700,8 @@ 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();
--
2.7.4