Stress Test: repetitive unloading and reloading driver can cause kernel panic on BYT using nocodec topology

[zhuqingliang]

Run soft/kmod_scripts/sof_bootloop.sh that repetitively unloads and reloads driver can cause kernel panic on BYT using nocodec topology.

description：
After 61 cycles ，prompt 'Removing sof_acpi_dev , Killed"
lsmod | grep sof ：
sof_acpi_dev 16384 -1
snd_sof_intel_bdw 20480 1 sof_acpi_dev
...
...

System Environment:
sof-v4.14 : 2879223
sof: d696d8f8bad1490575a8293e0982786300eb52db
soft: a25f4b0b02b51d186d2a9c6d73c8126784a61997
using test-ssp2-mclk-0-I2S-volume-s16le-s16le-48k-19200k-nocodec.tplg

reproduce steps:
./sof_bootloop.sh

log:
boot_59.boot.log
boot_60.boot.log
boot_61.boot.log
boot_62.boot.log
rmbox-t.log

[plbossart]

Can you clarify why I see this log in the dmesg files:
[ 210.916884] rt5651 i2c-10EC5651:00: Device with ID register 0xffff8c2d is not rt5651

This means you are not in nodec mode, you are using the ACPI ID to probe the codec. Or you must use the force-nocodec kconfig?

the PR #80 and PR #72 can fix this kind of kernel panic issue already.

[mengdonglin]

Stress test on driver unload/reload is not priority atm.

@lyakh it seem PR #130 still need to fix some check patch error. Please notify validation here when the PR is merged. Thanks!