lock debugging warning, probably bcm2835-isp related

Reproduce on an RPi4 using the bcm2711_defconfig debug options and load bcm2835_isp. Start with kernel/locking/mutex.c:938 and the trace through _vb2_fop_release in videobuf2_v4l2, then compare dmesg with bcm2835_isp loaded or blacklisted. Done means identifying and correcting the lock warning without introducing warnings under the listed lock-debug configuration.

Describe the bug
Building rpi-5.10.y with various lock debugging options enabled gives a kernel warning shortly after bcm2835 isp is loaded. The warning doesn't show up when bcm2835_isp is blacklisted.

[   13.933370] ------------[ cut here ]------------
[   13.937109] WARNING: CPU: 3 PID: 271 at kernel/locking/mutex.c:938 __mutex_lock+0x88c/0xac8
[   13.941159] DEBUG_LOCKS_WARN_ON(lock->magic != lock)
[   13.941177] Modules linked in: hid_logitech_dj(+) brcmfmac brcmutil sha256_generic cfg80211 bcm2835_codec(C) bcm2835_v4l2(C) rfkill v4l2_mem2mem videobuf2_vmalloc bcm2835_isp(C) bcm2835_mmal_vchiq(C) videobuf2_dma_contig videobuf2_memops videobuf2_v4l2 videobuf2_common raspberrypi_hwmon videodev vc_sm_cma(C) mc rpivid_mem nvmem_rmem uio_pdrv_genirq uio ip_tables x_tables ipv6
[   13.953252] CPU: 3 PID: 271 Comm: v4l_id Tainted: G         C        5.10.16-v7l+ #1
[   13.957181] Hardware name: BCM2711
[   13.961306] Backtrace: 
[   13.965480] [<c0caa6e0>] (dump_backtrace) from [<c0caaa8c>] (show_stack+0x20/0x24)
[   13.969475]  r7:ffffffff r6:00000000 r5:60000013 r4:c14f2a40
[   13.973513] [<c0caaa6c>] (show_stack) from [<c0cafc10>] (dump_stack+0xcc/0xf8)
[   13.977875] [<c0cafb44>] (dump_stack) from [<c0222370>] (__warn+0xfc/0x128)
[   13.982119]  r10:c1b7a670 r9:00000009 r8:c0cba0b0 r7:000003aa r6:00000009 r5:c0cba0b0
[   13.986356]  r4:c103146c r3:c1409094
[   13.990757] [<c0222274>] (__warn) from [<c0cab278>] (warn_slowpath_fmt+0xa4/0xd8)
[   13.994841]  r7:000003aa r6:c103146c r5:c1409048 r4:c102b64c
[   13.998921] [<c0cab1d8>] (warn_slowpath_fmt) from [<c0cba0b0>] (__mutex_lock+0x88c/0xac8)
[   14.003149]  r9:c4d105c4 r8:c2bc3900 r7:00000000 r6:c4614440 r5:00000000 r4:c4614914
[   14.007481] [<c0cb9824>] (__mutex_lock) from [<c0cba318>] (mutex_lock_nested+0x2c/0x34)
[   14.011839]  r10:c1409048 r9:c4d105c4 r8:c2bc3900 r7:c3409c10 r6:c4614440 r5:c4cff7c0
[   14.016106]  r4:c4614914
[   14.020331] [<c0cba2ec>] (mutex_lock_nested) from [<bf102b88>] (_vb2_fop_release+0x38/0x98 [videobuf2_v4l2])
[   14.024856] [<bf102b50>] (_vb2_fop_release [videobuf2_v4l2]) from [<bf102c1c>] (vb2_fop_release+0x34/0x38 [videobuf2_v4l2])
[   14.029443]  r7:c3409c10 r6:000a001d r5:c4cff7c0 r4:c4cff7c0
[   14.033803] [<bf102be8>] (vb2_fop_release [videobuf2_v4l2]) from [<bf1176e4>] (v4l2_release+0xdc/0xe8 [videodev])
[   14.038373]  r5:c4cff7c0 r4:c4614440
[   14.042922] [<bf117608>] (v4l2_release [videodev]) from [<c049d810>] (__fput+0xa4/0x270)
[   14.047345]  r5:c4519dd8 r4:c4cff7c0
[   14.051827] [<c049d76c>] (__fput) from [<c049d9f4>] (____fput+0x18/0x1c)
[   14.056313]  r9:c4d105c4 r8:c102df88 r7:c156be6c r6:c4d10000 r5:c4d10574 r4:00000000
[   14.060861] [<c049d9dc>] (____fput) from [<c024b10c>] (task_work_run+0xa8/0xe8)
[   14.065307] [<c024b064>] (task_work_run) from [<c020c390>] (do_work_pending+0x618/0x620)
[   14.069911]  r9:c4ce9fb0 r8:5ac3c35a r7:fffffe30 r6:00000084 r5:c0200204 r4:ffffe000
[   14.074300] [<c020bd78>] (do_work_pending) from [<c0200074>] (slow_work_pending+0xc/0x20)
[   14.078611] Exception stack(0xc4ce9fb0 to 0xc4ce9ff8)
[   14.082840] 9fa0:                                     00000000 00000000 0000006c 00000000
[   14.087169] 9fc0: 00000000 b6ff1170 00000000 00000006 00000000 00000000 004d1f50 00000000
[   14.091503] 9fe0: 004d1fc4 bef68c28 004c1638 b6f256bc 60000010 00000003
[   14.096096]  r10:00000006 r9:c4ce8000 r8:c0200204 r7:00000006 r6:00000000 r5:b6ff1170
[   14.100508]  r4:00000000
[   14.104866] irq event stamp: 4267
[   14.109156] hardirqs last  enabled at (4267): [<c0cbedc4>] _raw_spin_unlock_irq+0x30/0x50
[   14.109174] hardirqs last disabled at (4266): [<c0cbeae0>] _raw_spin_lock_irq+0x7c/0x80
[   14.109200] softirqs last  enabled at (3752): [<c02016f4>] __do_softirq+0x34c/0x60c
[   14.121955] softirqs last disabled at (3741): [<c022a478>] irq_exit+0x16c/0x1d4
[   14.121973] ---[ end trace c788e04c364b4c07 ]---

To reproduce
Build RPi4 kernel with lock debugging enabled

make bcm2711_defconfig
scripts/config \
	-e CONFIG_PROVE_LOCKING \
	-e CONFIG_DEBUG_RT_MUTEXES \
	-e CONFIG_DEBUG_SPINLOCK \
	-e CONFIG_DEBUG_MUTEXES \
	-e CONFIG_DEBUG_RWSEMS \
	-e CONFIG_DEBUG_LOCK_ALLOC \
	-e CONFIG_DEBUG_ATOMIC_SLEEP

Expected behaviour
No lock related warnings are shown.

System
RPi4 4GB, fully updated RPiOS lite with latest rpi-update kernel/firmware (Feb 16), kernel built from rpi-5.10.y branch with above options.

Logs
dmesg with warning: http://ix.io/2Qco
dmesg with bcm2835_isp blacklisted: http://ix.io/2Qcr

Additional context
I initially noticed the warning when enabling kernel debug options in LibreELEC