Please revert commit abb540b53976 ("usb: gadget: inode.c: fix
unbalanced spin_lock in ep0_write") on the 3.18 stable branch. The
upstream commit (b7bd98b7db9f) fixed a bug introduced in 4.0 by commit
96b62a571934 ("gadgetfs: really get rid of switching ->f_op").
Backporting it to older versions introduces a lock unbalance.
Ben.
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Ben Hutchings
Software Developer, Codethink Ltd.