Hi Felipe, On 5.03.2019 12:10, Radoslav Gerganov wrote: > In f_hidg_write() the write_spinlock is acquired before calling > usb_ep_queue() which causes a deadlock when dummy_hcd is being used. > This is because dummy_queue() callbacks into f_hidg_req_complete() which > tries to acquire the same spinlock. This is (part of) the backtrace when > the deadlock occurs: > > 0xffffffffc06b1410 in f_hidg_req_complete > 0xffffffffc06a590a in usb_gadget_giveback_request > 0xffffffffc06cfff2 in dummy_queue > 0xffffffffc06a4b96 in usb_ep_queue > 0xffffffffc06b1eb6 in f_hidg_write > 0xffffffff8127730b in __vfs_write > 0xffffffff812774d1 in vfs_write > 0xffffffff81277725 in SYSC_write > > Fix this by releasing the write_spinlock before calling usb_ep_queue() > > Signed-off-by: Radoslav Gerganov <rgerganov@xxxxxxxxxx> Did you have a chance to look at this patch? Please let me know if you need concrete steps for reproducing the deadlock. Thanks, Rado
