DeckLink Mini Recorder 4K streaming via NVidia GeForce GTX 1660

Hello!

Ubuntu 18.04.3
ffmpeg 4.2
Driver Version: 435.21
CUDA Version: 10.1
Nvenc version 9.1

Capture Device: DeckLink Mini Recorder 4K
GPU: NVidia GeForce GTX 1660

i need stream input video to mpegts udp:

ffmpeg \
    -use_wallclock_as_timestamps 1 \
    -loglevel debug \
    -hwaccel nvdec \
    -threads 8 -thread_type frame \
    -f decklink \
    -video_pts wallclock \
    -audio_pts wallclock \
    -draw_bars true \
    -raw_format yuv422p10 \
    -channels 2 \
    -i 'DeckLink Mini Recorder 4K' \
\
    -c:v h264_nvenc \
    -vsync 0 \
    -preset:v slow \
    -profile:v high \
    -level:v 4.2 \
    -rc cbr_hq \
    -rc-lookahead 32 \
    -surfaces 64 \
    -weighted_pred 1 \
    -pix_fmt yuv420p \
    -b:v 4.8M \
    -cq 17 \
    -qmin 1 \
    -qmax 18 \
    -g 12 \
    -refs 2 \
\
    -c:a libfdk_aac \
    -profile:a aac_he_v2 \
    -ac 2 \
    -ar 48000 \
    -af 'aresample=async=1' \
\
    -f mpegts 'udp://@239.0.0.1:2266?pkt_size=1316&fifo_size=1000000&buffer_size=100000000&overrun_nonfatal=1'

i get valid and successfull output:

[decklink @ 0x564090345bc0] Autodetected the input mode
[decklink @ 0x564090345bc0] Found Decklink mode 1920 x 1080 with rate 25.00(i)
Guessed Channel Layout for Input Stream #0.0 : stereo
Input #0, decklink, from 'DeckLink Mini Recorder 4K':
  Duration: N/A, start: 1570604250.716705, bitrate: 1107456 kb/s
    Stream #0:0: Audio: pcm_s16le, 48000 Hz, stereo, s16, 1536 kb/s
    Stream #0:1: Video: v210 (V210 / 0x30313256), yuv422p10le(top first), 1920x1080, 1105920 kb/s, 25 tbr, 1000k tbn, 1000k tbc
Stream mapping:
  Stream #0:1 -> #0:0 (v210 (native) -> h264 (h264_nvenc))
  Stream #0:0 -> #0:1 (pcm_s16le (native) -> aac (libfdk_aac))
Press [q] to stop, [?] for help
Output #0, mpegts, to 'udp://@239.0.0.1:2266?pkt_size=1316&fifo_size=1000000&buffer_size=100000000&overrun_nonfatal=1':
  Metadata:
    encoder         : Lavf58.32.104
    Stream #0:0: Video: h264 (h264_nvenc) (High), yuv420p(top coded first (swapped)), 1920x1080, q=1-18, 4800 kb/s, 25 fps, 90k tbn, 25 tbc
    Metadata:
      encoder         : Lavc58.56.101 h264_nvenc
    Side data:
      cpb: bitrate max/min/avg: 0/0/4800000 buffer size: 9600000 vbv_delay: N/A
    Stream #0:1: Audio: aac (libfdk_aac) (HE-AACv2), 48000 Hz, stereo, s16, 52 kb/s
    Metadata:
      encoder         : Lavc58.56.101 libfdk_aac
frame=   26 fps=0.0 q=0.0 size=       0kB time=00:00:00.96 bitrate=   0.0kbits/s speed=1.89x
frame=   39 fps= 38 q=0.0 size=       0kB time=00:00:01.47 bitrate=   0.0kbits/s speed=1.43x
frame=   52 fps= 34 q=0.0 size=       0kB time=00:00:01.98 bitrate=   0.0kbits/s speed=1.28x
...

but some time later (2-25 min) i get crush:

[decklink @ 0x55dc42b4ac00] Frame received (#17175) - Valid (5529600B) - QSize 0.000000MB
frame=17186 fps= 25 q=26.0 size=  419306kB time=00:11:27.39 bitrate=4997.1kbits/s speed=   1x
frame=17199 fps= 25 q=25.0 size=  419614kB time=00:11:27.90 bitrate=4997.0kbits/s speed=   1x
[decklink @ 0x55dc42b4ac00] Frame received (#17200) - Valid (5529600B) - QSize 0.000000MB
frame=17212 fps= 25 q=25.0 size=  419923kB time=00:11:28.41 bitrate=4997.0kbits/s speed=   1x
[decklink @ 0x55dc42b4ac00] Frame received (#17225) - Valid (5529600B) - QSize 0.000000MB
frame=17225 fps= 25 q=26.0 size=  420227kB time=00:11:28.92 bitrate=4996.9kbits/s speed=   1x
frame=17238 fps= 25 q=26.0 size=  420537kB time=00:11:29.43 bitrate=4996.9kbits/s speed=   1x
[decklink @ 0x55dc42b4ac00] Frame received (#17250) - Valid (5529600B) - QSize 0.000000MB
frame=17251 fps= 25 q=26.0 size=  420858kB time=00:11:29.95 bitrate=4997.0kbits/s speed=   1x
frame=17264 fps= 25 q=26.0 size=  421170kB time=00:11:30.50 bitrate=4996.7kbits/s speed=   1x
[decklink @ 0x55dc42b4ac00] Frame received (#17275) - Valid (5529600B) - QSize 0.000000MB
frame=17277 fps= 25 q=26.0 size=  421484kB time=00:11:31.01 bitrate=4996.7kbits/s speed=   1x
[decklink @ 0x55dc42b4ac00] Frame received (#17300) - Valid (5529600B) - QSize 63.378754MB
[decklink @ 0x55dc42b4ac00] Frame received (#17325) - Valid (5529600B) - QSize 195.402374MB
[decklink @ 0x55dc42b4ac00] Frame received (#17350) - Valid (5529600B) - QSize 327.425995MB
[decklink @ 0x55dc42b4ac00] Frame received (#17375) - Valid (5529600B) - QSize 459.449615MB
[decklink @ 0x55dc42b4ac00] Frame received (#17400) - Valid (5529600B) - QSize 591.473236MB
[decklink @ 0x55dc42b4ac00] Frame received (#17425) - Valid (5529600B) - QSize 723.496857MB
[decklink @ 0x55dc42b4ac00] Frame received (#17450) - Valid (5529600B) - QSize 855.520477MB
[decklink @ 0x55dc42b4ac00] Frame received (#17475) - Valid (5529600B) - QSize 987.544098MB
[decklink @ 0x55dc42b4ac00] Decklink input buffer overrun!
    Last message repeated 36 times
[decklink @ 0x55dc42b4ac00] Frame received (#17500) - Valid (5529600B) - QSize 1024.503296MB
[decklink @ 0x55dc42b4ac00] Decklink input buffer overrun!
    Last message repeated 49 times
[decklink @ 0x55dc42b4ac00] Frame received (#17525) - Valid (5529600B) - QSize 1024.503296MB
[decklink @ 0x55dc42b4ac00] Decklink input buffer overrun!
    Last message repeated 49 times
[decklink @ 0x55dc42b4ac00] Frame received (#17550) - Valid (5529600B) - QSize 1024.503296MB
[decklink @ 0x55dc42b4ac00] Decklink input buffer overrun!
    Last message repeated 49 times

if i use CPU encodind like libx264, all good, over9000 hours encode stream.
Why GPU crushes?
Perhaps the reason is out of sync equipment?

i found log:

kernel: [ 1240.080358] NVRM: GPU at PCI:0000:01:00: GPU-6caba61c-b997-efe4-1f42-012b974eadb5
kernel: [ 1240.080362] NVRM: GPU Board Serial Number:
kernel: [ 1240.080369] NVRM: Xid (PCI:0000:01:00): 31, pid=2196, Ch 00000038, intr 00000000. MMU Fault: ENGINE NVENC0 HUBCLIENT_NVENC0 faulted @ 0
x0_00001000. Fault is of type FAULT_PDE ACCESS_TYPE_VIRT_READ

hmm… it`s a driver bug.
when i do pipeline

decklink > libx246(q=1-3) -> local rtmp ( rtmp://localhost/feed/app ; 150Mbit/s) -> h264_nvenc(mpegts udp)

, it`s working fine!

syslog when i try do

ffmpeg -f decklink -i 'DeclLink Mini Recorder 4K' -c:v h264_nvenc -c:a libfdk_aac -f mpegts udp://xxx.xxx.xxx.xxx:foo

syslog:

kernel: [ 1240.080358] NVRM: GPU at PCI:0000:01:00: GPU-6caba61c-b997-efe4-1f42-012b974eadb5
kernel: [ 1240.080362] NVRM: GPU Board Serial Number:
kernel: [ 1240.080369] NVRM: Xid (PCI:0000:01:00): 31, pid=2196, Ch 00000038, intr 00000000. MMU Fault: ENGINE NVENC0 HUBCLIENT_NVENC0 faulted @ 0x0_00001000. Fault is of type FAULT_PDE ACCESS_TYPE_VIRT_READ