Other Parts Discussed in Thread: TDA4VM
Hi TI Expert,
Hope you're doing well.
Our customer found the black screen issue after loaded in car based on our TDA4VM-Q1 solution.
And the system log shows kernel panic warning as below:
Kernel boot: Kernel panic log
Starting kernel ...
[ 0.229932] debugfs: Directory 'pd:27' with parent 'pm_genpd' already present!
[ 0.237195] debugfs: Directory 'pd:26' with parent 'pm_genpd' already present!
[ 0.245444] debugfs: Directory 'pd:242' with parent 'pm_genpd' already present!
[ 0.252782] debugfs: Directory 'pd:241' with parent 'pm_genpd' already present!
[ 0.260089] debugfs: Directory 'pd:240' with parent 'pm_genpd' already present!
[ 0.267398] debugfs: Directory 'pd:239' with parent 'pm_genpd' already present!
[ 1.289084] Kernel panic - not syncing: VFS: Unable to mount root fs on unknown-block(0,0)
[ 1.297336] CPU: 1 PID: 1 Comm: swapper/0 Not tainted 5.10.65-g0f5c77529b #1
[ 1.304366] Hardware name: Texas Instruments J721E
[ 1.310095] Call trace:
[ 1.312544] dump_backtrace+0x0/0x1a0
[ 1.316195] show_stack+0x18/0x68
[ 1.319499] dump_stack+0xd0/0x12c
[ 1.322889] panic+0x16c/0x334
[ 1.325934] mount_block_root+0x2b8/0x34c
[ 1.329929] mount_root+0x70/0x80
[ 1.333230] prepare_namespace+0x130/0x170
[ 1.337312] kernel_init_freeable+0x25c/0x2a0
[ 1.341661] kernel_init+0x14/0x114
[ 1.345137] ret_from_fork+0x10/0x34
[ 1.348702] SMP: stopping secondary CPUs
[ 1.352615] Kernel Offset: disabled
[ 1.356092] CPU features: 0x0040022,20006008
[ 1.360347] Memory Limit: none
[ 1.363392] ---[ end Kernel panic - not syncing: VFS: Unable to mount root fs on unknown-block(0,0) ]---
Below scenario show above warning.
We use cellphone and connect to TDA4VM-Q1 in order output the info on car display, sometimes we will also see "kernel panic" during system boot up.
=> If we short the USB D+ & D- to GND on purpose on TDA4VM-Q1 ECU side, "kernel panic" will happen more often.

Not sure what might be the potential issue here, could you kindly share your comment based on previous experience?
Kindly let us know if you need further information.
Looking forward to your reply.
Thank you.










