iris: warnings when running fluster / FFmpeg-H.264-v4l2m2m on SM8250

[lumag]

Not having a better place to report mainline driver errors, reporting it here. Please point me to the correct place to report those errors.

Running fluster testsuite agaist the FFmpeg-H.264-v4l2m2m decoder generates a lot of warnings. Even if the stream is unsupported or if the userspace calls kernel driver in a wrong way, there should be no way to trigger WARNING splats, as those completely spam dmesg / kernel logs, possibly DoS'ing user machines.

[64473.860063] WARNING: drivers/media/common/videobuf2/videobuf2-core.c:1821 at vb2_start_streaming+0xd8/0x180, CPU#4: dec0:0:h264_v4l/10161
[64473.872744] Modules linked in:
[64473.875898] CPU: 4 UID: 1000 PID: 10161 Comm: dec0:0:h264_v4l Tainted: G        W           7.0.0-rc1-next-20260227-02920-g96b27e9eab44-dirty #4274 PREEMPT
[64473.890260] Tainted: [W]=WARN
[64473.893318] Hardware name: Qualcomm Technologies, Inc. Robotics RB5 (DT)
[64473.900204] pstate: 20400005 (nzCv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
[64473.907353] pc : vb2_start_streaming+0xd8/0x180
[64473.912016] lr : vb2_start_streaming+0x68/0x180
[64473.916677] sp : ffff800090b9bb20
[64473.920087] x29: ffff800090b9bb20 x28: ffff00008e930020 x27: 0000000000000000
[64473.927421] x26: 0000000040045612 x25: 0000000000000000 x24: ffffd86657868da8
[64473.934753] x23: ffffd866578dc2c8 x22: ffff0000926da180 x21: ffff00008a19c980
[64473.942084] x20: ffff00008a19c998 x19: 00000000fffffff0 x18: 0000000000000000
[64473.949416] x17: 0000000000000000 x16: 0000000000000000 x15: 0000ffffa574c884
[64473.956748] x14: 0000000000000000 x13: 0000000000000000 x12: ffffd86658d9b4d8
[64473.964084] x11: ffffd866590a42d8 x10: ffffd866580fa4e4 x9 : 0000000000000050
[64473.971416] x8 : ffff800090b9b990 x7 : ffff800090b9ba90 x6 : ffff800090b9ba50
[64473.978747] x5 : ffff800090b9b9d0 x4 : 0000000000000002 x3 : ffff800090b9ba14
[64473.986079] x2 : 0000000000000000 x1 : ffffd86659106000 x0 : ffff0000d0a10a38
[64473.993411] Call trace:
[64473.995935]  vb2_start_streaming+0xd8/0x180 (P)
[64474.000597]  vb2_core_streamon+0xd8/0x1c0
[64474.004722]  vb2_streamon+0x18/0x64
[64474.008321]  v4l2_m2m_ioctl_streamon+0x5c/0xa0
[64474.012895]  v4l_streamon+0x24/0x30
[64474.016493]  __video_do_ioctl+0x34c/0x400
[64474.020617]  video_usercopy+0x2ec/0xa24
[64474.024571]  video_ioctl2+0x18/0x7c
[64474.028169]  v4l2_ioctl+0x40/0x60
[64474.031585]  __arm64_sys_ioctl+0xac/0x104
[64474.035711]  invoke_syscall+0x48/0x104
[64474.039574]  el0_svc_common.constprop.0+0x40/0xe0
[64474.044417]  do_el0_svc+0x1c/0x28
[64474.047835]  el0_svc+0x50/0x2d0
[64474.051070]  el0t_64_sync_handler+0xa0/0xe4
[64474.055376]  el0t_64_sync+0x198/0x19c
[64474.059147] irq event stamp: 916
[64474.062471] hardirqs last  enabled at (915): [<ffffd866575e8738>] _raw_spin_unlock_irqrestore+0x6c/0x74
[64474.072118] hardirqs last disabled at (916): [<ffffd866575d2f6c>] el1_brk64+0x20/0x60
[64474.080155] softirqs last  enabled at (340): [<ffffd866564f2d28>] handle_softirqs+0x5c4/0x61c
[64474.088912] softirqs last disabled at (325): [<ffffd86656490294>] __do_softirq+0x14/0x20
[64474.097223] ---[ end trace 0000000000000000 ]---