Please could you provide your dmesg output?
This is what I am observing when playing a youtube video:
[ 2834.437962] =============================================
[ 2834.438509] [ INFO: possible recursive locking detected ]
[ 2834.443809] 4.0.0-linaro-lt-qcom #1 Not tainted
[ 2834.449186] ---------------------------------------------
[ 2834.453537] multiqueue0:src/1239 is trying to acquire lock:
[ 2834.459085] (&mlist->lock){+.+…}, at: [] get_registered_mmap_buf+0x68/0xf0
[ 2834.468455]
but task is already holding lock:
[ 2834.473148] (&mlist->lock){+.+…}, at: [] msm_vdec_start_streaming+0x420/0x51c
[ 2834.482951]
other info that might help us debug this:
[ 2834.487994] Possible unsafe locking scenario:
[ 2834.494500] CPU0
[ 2834.500298] ----
[ 2834.502728] lock(&mlist->lock);
[ 2834.508099] lock(&mlist->lock);
[ 2834.511398]
*** DEADLOCK ***
[ 2834.511776] May be due to missing lock nesting notation
[ 2834.517685] 3 locks held by multiqueue0:src/1239:
[ 2834.524618] #0: (&v4l2_dev->ioctl_lock){+.+.+.}, at: [] v4l2_ioctl+0xdc/0x174
[ 2834.534333] #1: (&inst->bufq[CAPTURE_PORT].lock){+.+.+.}, at: [] msm_vdec_streamon+0x50/0x108
[ 2834.543971] #2: (&mlist->lock){+.+…}, at: [] msm_vdec_start_streaming+0x420/0x51c
[ 2834.552658]
stack backtrace:
[ 2834.557697] CPU: 1 PID: 1239 Comm: multiqueue0:src Not tainted 4.0.0-linaro-lt-qcom #1
[ 2834.557699] Hardware name: Qualcomm Technologies, Inc. APQ 8016 SBC (DT)
[ 2834.557701] Call trace:
[ 2834.557707] [] dump_backtrace+0x0/0x124
[ 2834.557719] [] show_stack+0x10/0x1c
[ 2834.557724] [] dump_stack+0x80/0xc4
[ 2834.557729] [] __lock_acquire+0x158c/0x16b8
[ 2834.557733] [] lock_acquire+0x50/0x78
[ 2834.557738] [] mutex_lock_nested+0x54/0x3b8
[ 2834.557742] [] get_registered_mmap_buf+0x64/0xf0
[ 2834.557746] [] msm_comm_qbuf+0x3d4/0x8f4
[ 2834.557750] [] msm_vdec_start_streaming+0x464/0x51c
[ 2834.557756] [] vb2_start_streaming+0x64/0x178
[ 2834.557761] [] vb2_internal_streamon+0x134/0x16c
[ 2834.557765] [] vb2_streamon+0x38/0x60
[ 2834.557769] [] msm_vdec_streamon+0x58/0x108
[ 2834.557774] [] msm_vidc_streamon+0x28/0x38
[ 2834.557777] [] msm_v4l2_streamon+0x18/0x24
[ 2834.557782] [] v4l_streamon+0x1c/0x28
[ 2834.557787] [] __video_do_ioctl+0x23c/0x2b0
[ 2834.557792] [] video_usercopy+0x328/0x46c
[ 2834.557796] [] video_ioctl2+0x10/0x1c
[ 2834.557800] [] v4l2_ioctl+0xfc/0x174
[ 2834.557806] [] do_vfs_ioctl+0x37c/0x60c
[ 2834.557810] [] SyS_ioctl+0x80/0x98