Arch Linux User Repository

I finally had time to investigate the issue. It looks like that as of 11.5, the DesktopVideoHelper.service has to be running for the capture card to work properly.

Good news, they reproduced the issue. There's hope ;)

Got a response, they can't reproduce on Ubuntu 16.04 with v4.8.2 Mainline PPA Build. I'll keep you posted

DarenK, yeah. I also upgraded the kernel to 4.8. I'm just about to rollback to 4.7 if I can.

I sent an email to developer-pro@blackmagicdesign.com, still no response

Damn, I updated the kernel and didn't think the drivers would malfunction. Any updates?

Apparently even the latest version crashes on 4.8.2-1-ARCH at boot oct. 19 10:32:18 mymachine.mynetwork.net kernel: usercopy: kernel memory overwrite attempt detected to ffff8803ccabfe10 (<process stack>) (16 bytes) oct. 19 10:32:18 mymachine.mynetwork.net kernel: ------------[ cut here ]------------ oct. 19 10:32:18 mymachine.mynetwork.net kernel: kernel BUG at mm/usercopy.c:75! oct. 19 10:32:18 mymachine.mynetwork.net kernel: invalid opcode: 0000 [#5] PREEMPT SMP oct. 19 10:32:18 mymachine.mynetwork.net kernel: Modules linked in: fuse nfsv3 nfs_acl rpcsec_gss_krb5 auth_rpcgss oid_registry nfsv4 dns_resolver nfs lockd grace sunrpc fscache snd_hda_codec_hdmi snd_hda_codec_re oct. 19 10:32:18 mymachine.mynetwork.net kernel: evdev tpm_tis acpi_pad mac_hid tpm_tis_core tpm sch_fq_codel vboxnetflt(O) vboxnetadp(O) pci_stub vboxpci(O) vboxdrv(O) ip_tables x_tables ext4 crc16 jbd2 fscrypto oct. 19 10:32:18 mymachine.mynetwork.net kernel: CPU: 3 PID: 958 Comm: BlackmagicFirmw Tainted: P D O 4.8.2-1-ARCH #1 oct. 19 10:32:18 mymachine.mynetwork.net kernel: Hardware name: ASUS All Series/H97M-PLUS, BIOS 2603 02/22/2016 oct. 19 10:32:18 mymachine.mynetwork.net kernel: task: ffff8803ccac2ac0 task.stack: ffff8803ccabc000 oct. 19 10:32:18 mymachine.mynetwork.net kernel: RIP: 0010:[<ffffffff81205e3f>] [<ffffffff81205e3f>] __check_object_size+0x13f/0x1d6 oct. 19 10:32:18 mymachine.mynetwork.net kernel: RSP: 0018:ffff8803ccabfd98 EFLAGS: 00010282 oct. 19 10:32:18 mymachine.mynetwork.net kernel: RAX: 0000000000000063 RBX: ffff8803ccabfe10 RCX: 0000000000000000 oct. 19 10:32:18 mymachine.mynetwork.net kernel: RDX: 0000000000000000 RSI: ffff88041facdba8 RDI: ffff88041facdba8 oct. 19 10:32:18 mymachine.mynetwork.net kernel: RBP: ffff8803ccabfdb8 R08: 000000000009dd9f R09: 0000000000000005 oct. 19 10:32:18 mymachine.mynetwork.net kernel: R10: 0000000000000541 R11: 0000000000000381 R12: 0000000000000010 oct. 19 10:32:18 mymachine.mynetwork.net kernel: R13: 0000000000000000 R14: ffff8803ccabfe20 R15: 00007fff8fa12320 oct. 19 10:32:18 mymachine.mynetwork.net kernel: FS: 00007f401049f4c0(0000) GS:ffff88041fac0000(0000) knlGS:0000000000000000 oct. 19 10:32:18 mymachine.mynetwork.net kernel: CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 oct. 19 10:32:18 mymachine.mynetwork.net kernel: CR2: 00000000016c7028 CR3: 00000003cc856000 CR4: 00000000001406e0 oct. 19 10:32:18 mymachine.mynetwork.net kernel: Stack: oct. 19 10:32:18 mymachine.mynetwork.net kernel: ffff8803ccabfe10 0000000000000010 00007fff8fa12320 ffff8803dfb99e00 oct. 19 10:32:18 mymachine.mynetwork.net kernel: ffff8803ccabfde0 ffffffffa0680b90 ffff8803ccabfe10 00007fff8fa12320 oct. 19 10:32:18 mymachine.mynetwork.net kernel: ffff88040c66d628 ffff8803d47dc800 ffffffffa067c83d 0000000000000001 oct. 19 10:32:18 mymachine.mynetwork.net kernel: Call Trace: oct. 19 10:32:18 mymachine.mynetwork.net kernel: [<ffffffffa0680b90>] bm_copy_from_user+0x20/0x40 [blackmagic_io] oct. 19 10:32:18 mymachine.mynetwork.net kernel: [<ffffffffa067c83d>] _ZN18IoctlMessageKernel6unpackEv+0x3d/0x140 [blackmagic_io] oct. 19 10:32:18 mymachine.mynetwork.net kernel: [<ffffffffa064566a>] ? _ZN20UserClientClassLinux5ioctlEjm+0x6a/0xa0 [blackmagic_io] oct. 19 10:32:18 mymachine.mynetwork.net kernel: [<ffffffff811b3cfe>] ? handle_mm_fault+0x3ee/0x14a0 oct. 19 10:32:18 mymachine.mynetwork.net kernel: [<ffffffffa067cc8a>] ? bmio_ioctl+0x1a/0x30 [blackmagic_io] oct. 19 10:32:18 mymachine.mynetwork.net kernel: [<ffffffff8121c313>] ? do_vfs_ioctl+0xa3/0x5f0 oct. 19 10:32:18 mymachine.mynetwork.net kernel: [<ffffffff81227547>] ? __fget+0x77/0xb0 oct. 19 10:32:18 mymachine.mynetwork.net kernel: [<ffffffff8121c8d9>] ? SyS_ioctl+0x79/0x90 oct. 19 10:32:18 mymachine.mynetwork.net kernel: [<ffffffff815f7cf2>] ? entry_SYSCALL_64_fastpath+0x1a/0xa4 oct. 19 10:32:18 mymachine.mynetwork.net kernel: Code: 87 71 81 48 0f 45 d0 48 c7 c6 60 a5 72 81 48 c7 c0 db 43 73 81 48 0f 45 f0 4d 89 e1 48 89 d9 48 c7 c7 18 0d 73 81 e8 67 02 f7 ff <0f> 0b 48 89 df e8 77 76 e6 oct. 19 10:32:18 mymachine.mynetwork.net kernel: RIP [<ffffffff81205e3f>] __check_object_size+0x13f/0x1d6 oct. 19 10:32:18 mymachine.mynetwork.net kernel: RSP <ffff8803ccabfd98> oct. 19 10:32:18 mymachine.mynetwork.net kernel: ---[ end trace 0139f39ddae78683 ]---

I think that pulseaudio is using the snd_blackmagic_io module, therefore preventing it from being unloaded.

:: Running post-transaction hooks... (1/3) Install DKMS modules ==> dkms install -m blackmagic -v 10.8a2 -k 4.7.4-1-ARCH ==> dkms install -m blackmagic -v 10.8a2 -k 4.7.4-1-ck Good news! Module version 10.8a2 for blackmagic.ko exactly matches what is already found in kernel 4.7.4-1-ck. DKMS will not replace this module. You may override by specifying --force. ==> dkms install -m blackmagic-io -v 10.8a2 -k 4.7.4-1-ARCH ==> dkms install -m blackmagic-io -v 10.8a2 -k 4.7.4-1-ck Good news! Module version 10.8a2 for blackmagic-io.ko exactly matches what is already found in kernel 4.7.4-1-ck. DKMS will not replace this module. You may override by specifying --force. Good news! Module version 10.8a2 for snd_blackmagic-io.ko exactly matches what is already found in kernel 4.7.4-1-ck. DKMS will not replace this module. You may override by specifying --force. modprobe: FATAL: Module blackmagic_io is in use. ERR The existing blackmagic-io driver was not able to be unloaded ERR Please check 'dmesg' for more information

Updated to 10.8a2.

I sent him an email