Nx CSI have no signal cause kernel problem

NX Jetspack :Jetpack 4.4 DP。
I use LT6911,it’s a chip make HDMI to CSI。If i give HDMI signal,CSI can have singal out.If i do not give HDMI,CSI will always high level.

    The problem is,if i do not give HDMI,driver may cause kernel problem.And i can not close /dev/video0,
   This problem only happen in Jetson nx.
   Jetson nano have no such problem,in jetson nano,i can open /dev/video0,than give CSI singal.Can Restore display。

Can give some advice.If do not give CSI signal,driver can wait signal without causing kernel panic.

If you want to increase the timeout time to wait the input from sensor you can modify the #define CAPTURE_TIMEOUT_MS 2500 in vi5_fops.c to delay the panic.

I do not modify #define CAPTURE_TIMEOUT_MS 2500 in vi5_fops.c。But some times,can restore if give CSI signal,and kernel keep print “request timed out after 2500 ms”.In most cases,kernel will print “unexpected response frome camera processor” and stop print “request timed out after 2500 ms”.This time cloes /dev/video0.The kernel will panic.I think not through modify #define CAPTURE_TIMEOUT_MS 2500.can solve this problem。

It seems do not close two kthread in vi5_fops.c .vi5_fops is open two kthread,but not close.If kernel print “unexpected response frome camera processor”.

What condition will cause the panic?

If no CSI signal,than open /dev/video0,(my driver is add in kernel)。Kernel print “request timed out after 2500 ms” is normal。
Than wait.
Follorwing,If kernel print “vi capture release failed”,It will result problem.
This time ,if you close /dev/video0 ,it will failed.
And kernel print panic message.

Do you send stream_off before close the /dev/video0 ?

Actually No.
I am not close /dev/video0,The stream_on,and close CSI signal.
I know this action is unusual.But our manager want this function.
And Jetson nano Looks like it can。
Can give some advices?

There is no update from you for a period, assuming this is not an issue any more.
Hence we are closing this topic. If need further support, please open a new one.

I think the default driver won’t consider this kind special use case. What’s the purpose for this use case?