linux kernel starting stops after 4 seconds

[fei_4_xu]

Hi,

I'm using a customized i.mx8qxp board, so very likely there are some device tree mistakes in the hardware bring-up phase.

My current problem is that the board stops in the middle of kernel starting, like this:

Starting kernel ...

[    0.000000] Booting Linux on physical CPU 0x0000000000 [0x410fd042]
[    0.000000] Linux version 5.4.70-00114-g4f2631b022d8-dirty (user@machine) (gcc version 9.2.0 (GCC)) #13 SMP PREEMPT Sat Jul 3 22:57:58 CST 2021
[    0.000000] Machine model: Freescale i.MX8QXP MEK
[    0.000000] efi: Getting EFI parameters from FDT:
[    0.000000] efi: UEFI not found.
[    0.000000] Reserved memory: created CMA memory pool at 0x0000000096000000, size 960 MiB
[    0.000000] OF: reserved mem: initialized node linux,cma, compatible id shared-dma-pool
[    0.000000] Reserved memory: created DMA memory pool at 0x0000000090000000, size 0 MiB
[    0.000000] OF: reserved mem: initialized node vdev0vring0@90000000, compatible id shared-dma-pool
[    0.000000] Reserved memory: created DMA memory pool at 0x0000000090008000, size 0 MiB
[    0.000000] OF: reserved mem: initialized node vdev0vring1@90008000, compatible id shared-dma-pool
[    0.000000] Reserved memory: created DMA memory pool at 0x0000000090010000, size 0 MiB
[    0.000000] OF: reserved mem: initialized node vdev1vring0@90010000, compatible id shared-dma-pool
[    0.000000] Reserved memory: created DMA memory pool at 0x0000000090018000, size 0 MiB
[    0.000000] OF: reserved mem: initialized node vdev1vring1@90018000, compatible id shared-dma-pool
[    0.000000] Reserved memory: created DMA memory pool at 0x0000000090400000, size 1 MiB
[    0.000000] OF: reserved mem: initialized node vdevbuffer, compatible id shared-dma-pool
[    0.000000] NUMA: No NUMA configuration found
[    0.000000] NUMA: Faking a node at [mem 0x0000000080200000-0x00000008bfffffff]
[    0.000000] NUMA: NODE_DATA [mem 0x8bf9f3500-0x8bf9f4fff]
[    0.000000] Zone ranges:
[    0.000000]   DMA32    [mem 0x0000000080200000-0x00000000ffffffff]
[    0.000000]   Normal   [mem 0x0000000100000000-0x00000008bfffffff]
[    0.000000] Movable zone start for each node
[    0.000000] Early memory node ranges
[    0.000000]   node   0: [mem 0x0000000080200000-0x0000000083ffffff]
...
...
...
...
[    3.878407] debugfs: Directory '59040000.sai' with parent 'bt-sco-audio' already present!
[    3.886780] asoc-simple-card sound-bt-sco: bt-sco-pcm-wb <-> 59040000.sai mapping ok
[    3.894549] asoc-simple-card sound-bt-sco: ASoC: no DMI vendor name!
[    3.900947] debugfs: File 'Playback' in directory 'dapm' already present!
[    3.907750] debugfs: File 'Capture' in directory 'dapm' already present!
[    3.922745] adv7511 19-003d: 19-003d supply avdd not found, using dummy regulator
[    3.930369] adv7511 19-003d: 19-003d supply dvdd not found, using dummy regulator
[    3.937911] adv7511 19-003d: 19-003d supply pvdd not found, using dummy regulator
[    3.945446] adv7511 19-003d: 19-003d supply a2vdd not found, using dummy regulator
[    3.953066] adv7511 19-003d: 19-003d supply v3p3 not found, using dummy regulator
[    3.960624] adv7511 19-003d: 19-003d supply v1p2 not found, using dummy regulator
[    3.968814] adv7511 19-003d: Probe failed. Remote port 'dsi_host@56228000' disabled
[    3.976585] i2c i2c-19: LPI2C adapter registered
[    3.983324] adv7511 20-003d: 20-003d supply avdd not found, using dummy regulator
[    3.990903] adv7511 20-003d: 20-003d supply dvdd not found, using dummy regulator
[    3.998450] adv7511 20-003d: 20-003d supply pvdd not found, using dummy regulator
[    4.005985] adv7511 20-003d: 20-003d supply a2vdd not found, using dummy regulator
[    4.013618] adv7511 20-003d: 20-003d supply v3p3 not found, using dummy regulator
[    4.021174] adv7511 20-003d: 20-003d supply v1p2 not found, using dummy regulator
[    4.029367] adv7511 20-003d: Probe failed. Remote port 'dsi_host@56248000' disabled
[    4.037112] i2c i2c-20: LPI2C adapter registered

I deleted some log in the middle, but the ending log (timestamp of 4.037112) is same as the original log.

So I'm very curious, why the kernel seemed to be stopped?

If there is something wrong in the board's hardware, which module (device tree node) should I disable for a test? Can I tell from the log sequence?

[fei_4_xu]

I searched for 56248000 and I was lucky: there is only 1 file containing it, which is lvds related. 

I disabled the whole lvds_subsystem and I am able to move on (there are still other error, though)

&lvds_subsys {
	status = "disabled";
};

[igorpadykov · Accepted solution]

Hi Fei

had board passed ddr test and necessary changes were performed in image

https://community.nxp.com/t5/i-MX-Processors-Knowledge-Base/i-MX-8-8X-Family-DDR-Tools-Release/ta-p/...

For kernel stop one can try to remove "adv7511" and check if it helps, also one can try to debug it

using AN12631  Normal and Secure Debug for i.MX8/8X Family of Applications Processors

Best regards
igor