Summary for a software lockup issue on L4.14.y

[#1]

This is a summary for the software lockup issue found in the following platform:

−i.MX8/8X

−Linux 4.14.98_2.3.3

Issue description:

•Issue happens during the boot procedure, at the systemd stage.

•The symptom of the issue:

−From user perspective, the symptom varies, but mainly fall into several types:

§At the console, there may be login prompt, but no response (only echo) when input user/password. Unable to login.

§Some user service in systemd failed to start. E.g. weston.

−When checking the task status using sysrq (w/t), many tasks, including some kernel core tasks stays in “D” (uninterruptable sleep) state. E.g. agetty, login, chvt, etc.

•Kernel itself is still alive. This can be verified by triggering some drivers, such as plugin a USB device.

Issue can be reproduced on MEK through long time stress.

Please refer to the doc/patch attached for details.