Initializing Decoder (nvhost-nvdec) takes ONE minute on L4T R32.7.3

Autonomous Machines Jetson & Embedded Systems Jetson TX2
1

Just moved to
+Linux4Tegra release: R32.7.3
+JetPack release: 4.6.3

And the first open of the decoder device /dev/nvhost-nvdec now takes about 1 minute.

Ex:

// slow on the first call
int fd = v4l2_open("/dev/nvhost-nvdec" , O_NONBLOCK | O_RDWR);

The same behavior can be seen from the command line if you start nvdec to first time:

time echo on > /sys/devices/13e10000.host1x/15480000.nvdec/power/control

real    1m1.904s
user    0m0.000s
sys     0m0.000s

Has anyone else experienced this?
Where to start looking?

Thanks for your time!

3

Hi,
We have two samples demonstrating hardware coding:

/usr/src/jetson_multimedia_api/samples/00_video_decode
/usr/src/jetson_multimedia_api/samples/unittest_samples/decoder_unit_sample

We don’t see this issue while running the samples. You may give it a try and see if the issue occurs.

4

Thanks Dane, i see the issue also with the sample codes, they both perform the same operation i described:

int fd = v4l2_open("/dev/nvhost-nvdec" , O_NONBLOCK | O_RDWR);

I’ve continued examining what happens and it appears that:

  1. The NVDEC firmware is not loaded at bootup, load is triggered by the v4l2_open(…) call
  2. The firmware load times out after 60s but the NVDEC is surprisingly funcitoning after that

To my understanding,

  1. open(…) triggers driver to request the firmware “tegra18x/nvhost_nvdec_bl030_prod.fw”
  2. kernel sends an event to udev asking for the firmware
  3. udev appears to timeout on on ADD
udevadm monitor --property

KERNEL[30.980823] add      /devices/13e10000.host1x/15480000.nvdec/firmware/tegra18x!nvhost_nvdec_bl030_prod.fw (firmware)
ACTION=add
DEVPATH=/devices/13e10000.host1x/15480000.nvdec/firmware/tegra18x!nvhost_nvdec_bl030_prod.fw
SUBSYSTEM=firmware
FIRMWARE=tegra18x/nvhost_nvdec_bl030_prod.fw
TIMEOUT=60
ASYNC=0
SEQNUM=3644

UDEV  [30.981783] add      /devices/13e10000.host1x/15480000.nvdec/firmware/tegra18x!nvhost_nvdec_bl030_prod.fw (firmware)
ACTION=add
DEVPATH=/devices/13e10000.host1x/15480000.nvdec/firmware/tegra18x!nvhost_nvdec_bl030_prod.fw
SUBSYSTEM=firmware
FIRMWARE=tegra18x/nvhost_nvdec_bl030_prod.fw
TIMEOUT=60
ASYNC=0
SEQNUM=3644
USEC_INITIALIZED=30981664

Above operation hangs for 60s (presumably hitting the timeout time).

5

Hi,
Please check if you observe the issue while running default 00_video_decode or decoder_unit_sample. We would expect default samples work well. If it does not work in your setup, we would suggest re-flash system image and you can upgrade to Jetpack 4.6.4(r32.7.4)

6

Yes, the same issue is observed.

7

Sorry for the late response, have you managed to get issue resolved or still need the support? Thanks

8

hey, yes thanks! It was unrelated to anything in vanilla L4T, so not a general issue.