On Sun, Oct 31, 2021 at 7:52 PM Bart Van Assche [off-list ref] wrote:

On 10/31/21 16:19, Justin Piszcz wrote:

quoted

Diff between 5.14 and 5.15 .config files-- could it be something to do with
CONFIG_IOMMU_DEFAULT_DMA_LAZY=y?

That's hard to say. Is CONFIG_MAGIC_SYSRQ enabled? If not, please enable
it and hit Alt-Printscreen-t (dump task list; see also
Documentation/admin-guide/sysrq.rst) and share the contents of the
kernel log. If that would not be convenient, please try to bisect this
issue.

[ .. ]

It appears at this point in the boot process the keyboard (USB and
PS2) are not yet available and/or do not respond in this scenario (I
do have CONFIG_MAGIC_SYSRQ enabled+have used it in the past).  I'll
build the prior 5.15-rc(1-7) to check where it stopped working and
reply back to the list when I have that info.

Thanks!

Justin.