Good afternoon, dear Nvidia!
Sometimes we are loosing 1 frame among few thousand with the message of:
Host read timeout at address 54081908
Could you tell me why does it occur? We strongly need each frame and this picture is failing whole our system.
There are a lot of frames in the dmesg but only final frame we have lost.
You could find line with Host read etc.
I’m attaching dmesg but there is nothing interesting.
3135.log (15.3 MB)
It is not the first time when we are loosing frame and I see such a message in dmesg in this situation, so we need a solution how could we fix or prevent this situation.
Do you run v4l2-ctl to capture?
Yes:
v4l2-ctl --set-ctrl=single_shot_mode=1 --set-ctrl=sensor_mode=3 --set-fmt-video=width=1824,height=2284,pixelformat='Y12' --stream-count=1 --stream-mmap --stream-to=/home/rocel/image0.raw --device=/dev/video0
What’s single_shot_mode?
Mode where we reduced buf size from 3 to 1 because your driver is working in such manner that if you do less that 3 frames it will not give upstairs to the V4L2 a frame, but we want to do photos so we reduced buff size to 1 for this purpose - this is single shot mode.
Also we have problems with simultaneous CSI working. When we want to do a big picture from 4 CSI at once sometimes 1 of this CSI is saying that there is incorrect line state on the CLK (CSI1_CILA_STATUS_0 0 bit). This is the option only when we are taking picture from 4 camera simultaneously. When we tried to prove that it is the case we tried to do more than 30000 pics on each camera on our device and there was no one lose. We verified all 4 channels separately and there was not frame drops but when we try to work with 4 camera in the same time we start to loosing frames in the cases I described.
We are using 4 channels and if we lost a frame because of CSI it always losing in CSI[3] (CSI1 channel A) so we think that CPU could prioritize first lanes and could be that it is hard for it to receive 4 pics simultaneously. Like he doesn’t have time to set up the distant channel for transmission and we lose the picture from it.
If we lose frame because of Host read timeout at address 54081908 it always losing in CSI[2] (CSI2 chan B)
What’s the result without reduce the buf to 1?
Without reducing buffer to 1 you cannot receive single shot image, because you driver have been written in such a way that if buffer is not full it will not send picture upstairs to the userspace