I ask this because I am running a weird config, but I think this was working fine with R28.1 and R28.2-Pre-Release, however when trying to use it with R28.2.1, although it seems it works (I can successfully read the virtual video device), each time kernel errors are shown.
I have just R28.2.1 rootfs (patched by apply_binaries.sh and apt updated) on a SATA SSD partition, and boot it from eMMC through an extlinux.conf entry (R28.2.1 kernel image is copied into eMMC0 /boot). I have no post-install step (no CUDA, …).
I have built and installed v4l2loopback module as I previously did following this and installed my virtual video device as /dev/video2:
sudo modprobe v4l2loopback devices=1 video_nr=2
Each time I try to use v4l2sink
gst-launch-1.0 -e videotestsrc is-live=true ! 'video/x-raw, format=BGR, width=640, height=480, framerate=30/1' ! tee ! v4l2sink device=/dev/video2
I see these errors :
dmesg --follow
...
[ 9122.756817] Unknown pixelformat 0x30395056
[ 9122.760968] ------------[ cut here ]------------
[ 9122.765577] WARNING: at ffffffc0007a7240 [verbose debug info unavailable]
[ 9122.772351] Modules linked in: v4l2loopback(O) fuse ipt_MASQUERADE nf_nat_masquerade_ipv4 iptable_nat nf_nat_ipv4 xt_addrtype iptable_filter ip_tables xt_conntrack nf_nat br_netfilter overlay bcmdhd bluedroid_pm pci_tegra [last unloaded: v4l2loopback]
[ 9122.796235] CPU: 0 PID: 5354 Comm: videotestsrc0:s Tainted: G W O 4.4.38-tegra #1
[ 9122.804655] Hardware name: quill (DT)
[ 9122.808309] task: ffffffc059a2d780 ti: ffffffc056eb8000 task.ti: ffffffc056eb8000
[ 9122.815781] PC is at v4l_enum_fmt+0x1270/0x1608
[ 9122.820302] LR is at v4l_enum_fmt+0x1270/0x1608
[ 9122.824821] pc : [<ffffffc0007a7240>] lr : [<ffffffc0007a7240>] pstate: 80000045
[ 9122.832202] sp : ffffffc056ebbbf0
[ 9122.835508] x29: ffffffc056ebbbf0 x28: ffffffc001348730
[ 9122.840826] x27: 0000000000000000 x26: ffffffc056ebbd20
[ 9122.846145] x25: 0000007f88005730 x24: ffffffbffc02aaa8
[ 9122.851462] x23: ffffffc124db5d80 x22: ffffffc19c95fe00
[ 9122.856782] x21: ffffffbffc02aaa8 x20: 0000000000000000
[ 9122.862100] x19: ffffffc056ebbd20 x18: 0000000000000000
[ 9122.867418] x17: 0000007f8de98b20 x16: ffffffc0001e6610
[ 9122.872736] x15: 0000007f8e212000 x14: 0fffffffffffffff
[ 9122.878055] x13: 0000000000000018 x12: ffffffc001299000
[ 9122.883374] x11: 0000000000000002 x10: 00000000000008b0
[ 9122.888693] x9 : ffffffc056ebb9b0 x8 : ffffffc059a2e090
[ 9122.894010] x7 : 0000000000000400 x6 : 000000000019d7e3
[ 9122.899329] x5 : 0000000000000000 x4 : ffffffc059a2e098
[ 9122.904647] x3 : ffffffc19cb4d3cc x2 : ffffffc1eafd3228
[ 9122.909965] x1 : 0000000000000000 x0 : 000000000000001e
[ 9122.917090] ---[ end trace fdd57256678830e6 ]---
[ 9122.921698] Call trace:
[ 9122.924141] [<ffffffc0007a7240>] v4l_enum_fmt+0x1270/0x1608
[ 9122.929704] [<ffffffc0007a7dcc>] __video_do_ioctl+0x22c/0x2a0
[ 9122.935439] [<ffffffc0007a782c>] video_usercopy+0x254/0x5ac
[ 9122.941000] [<ffffffc0007a7b98>] video_ioctl2+0x14/0x1c
[ 9122.946214] [<ffffffc0007a2b8c>] v4l2_ioctl+0xbc/0xcc
[ 9122.951257] [<ffffffc0001e6350>] do_vfs_ioctl+0x324/0x5e4
[ 9122.956643] [<ffffffc0001e6694>] SyS_ioctl+0x84/0x98
[ 9122.961600] [<ffffffc000084ff0>] el0_svc_naked+0x24/0x28
[ 9122.967138] Unknown pixelformat 0x43564548
[ 9122.971325] ------------[ cut here ]------------
[ 9122.975956] WARNING: at ffffffc0007a7240 [verbose debug info unavailable]
[ 9122.982738] Modules linked in: v4l2loopback(O) fuse ipt_MASQUERADE nf_nat_masquerade_ipv4 iptable_nat nf_nat_ipv4 xt_addrtype iptable_filter ip_tables xt_conntrack nf_nat br_netfilter overlay bcmdhd bluedroid_pm pci_tegra [last unloaded: v4l2loopback]
[ 9123.006668] CPU: 1 PID: 5354 Comm: videotestsrc0:s Tainted: G W O 4.4.38-tegra #1
[ 9123.015093] Hardware name: quill (DT)
[ 9123.018787] task: ffffffc059a2d780 ti: ffffffc056eb8000 task.ti: ffffffc056eb8000
[ 9123.026286] PC is at v4l_enum_fmt+0x1270/0x1608
[ 9123.030810] LR is at v4l_enum_fmt+0x1270/0x1608
[ 9123.035333] pc : [<ffffffc0007a7240>] lr : [<ffffffc0007a7240>] pstate: 80000045
[ 9123.042715] sp : ffffffc056ebbbf0
[ 9123.046024] x29: ffffffc056ebbbf0 x28: ffffffc001348730
[ 9123.051348] x27: 0000000000000000 x26: ffffffc056ebbd20
[ 9123.056670] x25: 0000007f88005780 x24: ffffffbffc02aaa8
[ 9123.061991] x23: ffffffc124db5d80 x22: ffffffc19c95fe00
[ 9123.067315] x21: ffffffbffc02aaa8 x20: 0000000000000000
[ 9123.072636] x19: ffffffc056ebbd20 x18: 0000000000000000
[ 9123.077959] x17: 0000007f8de98b20 x16: ffffffc0001e6610
[ 9123.083281] x15: 0000007f8e212000 x14: 0ffffffffffffffe
[ 9123.088603] x13: 0000000000000020 x12: ffffffc001299000
[ 9123.093925] x11: 0000000000000002 x10: 00000000000008b0
[ 9123.099249] x9 : ffffffc056ebb9b0 x8 : ffffffc059a2e090
[ 9123.104571] x7 : 0000000000000400 x6 : 00000000003835e5
[ 9123.109894] x5 : 0000000000000000 x4 : ffffffc059a2e098
[ 9123.115218] x3 : ffffffc19cb4d3cc x2 : ffffffc07033f0a8
[ 9123.120543] x1 : 0000000000000000 x0 : 000000000000001e
[ 9123.127796] ---[ end trace fdd57256678830e7 ]---
[ 9123.132408] Call trace:
[ 9123.134853] [<ffffffc0007a7240>] v4l_enum_fmt+0x1270/0x1608
[ 9123.140419] [<ffffffc0007a7dcc>] __video_do_ioctl+0x22c/0x2a0
[ 9123.146157] [<ffffffc0007a782c>] video_usercopy+0x254/0x5ac
[ 9123.151721] [<ffffffc0007a7b98>] video_ioctl2+0x14/0x1c
[ 9123.156940] [<ffffffc0007a2b8c>] v4l2_ioctl+0xbc/0xcc
[ 9123.161986] [<ffffffc0001e6350>] do_vfs_ioctl+0x324/0x5e4
[ 9123.167376] [<ffffffc0001e6694>] SyS_ioctl+0x84/0x98
[ 9123.172335] [<ffffffc000084ff0>] el0_svc_naked+0x24/0x28
The Unknown pixelformat 0x30395056 and 0x43564548 are always there, whatever format I specify before v4l2sink (NV12, I420, YUY2, GRAY8…).
Same with other video sources (nvcamerasrc, nvarguscamerasrc).
Is it just my case or is it reproducible ?
[EDIT: This may be related to v4l2loopback version. It works with 0.9.1 on R28.2-Pre but fails with 0.12.0 on R28.2.1]