Re: Hang at "loading initial ramdisk ..." on Generation 11 CPU, Gen 9, 7, and 6 work.

[Philippe Gerum <rpm@xenomai.org>]

"Rosenow, James" <jim.rosenow@mts.com> writes:

>> "Rosenow, James" <jim.rosenow@mts.com> writes:
>> 
>> > We have a COM express carrier with an on-board SSD.  The SSD has
>> > Ubuntu 22.04 installed on it, on top of that, I've installed the
>> > latest Xenomai (master) alongside the 'v6.5-dovetail-rebase' kernel
>> > from the linux-dovetail repository .  Given that our board supports
>> > COM Express, we can easily swap between various processors and have
>> > been doing so looking for the best price/performance ratio and of
>> > course, low latency.
>> >
>> > I have two modules that I am currently testing, an i3-11100HE and an i7-
>> 9850HL.  Since the SSD is on the base board, I'm running the exact same
>> version of Ubuntu, kernel and root file system regardless of the installed
>> processor board.
>> >
>> > The gen9 processor boots and runs the Xenomai kernel without any
>> > trouble at all.  I'm having SMI issues but that is another subject.
>> > When I put the gen11 board on the carrier, it hangs at 'loading
>> > initial ramdisk .'.  It is noteworthy that if I interrupt grub and
>> > select the stock 6.5.x Ubuntu kernel on either, both gen 11 and gen 9
>> > boot and run fine.  I've verified the Xenomai kernel runs fine on
>> > generation 7 and 6 CPU's as well.
>> >
>> > I've searched the web for possible reasons why Linux would hang at that
>> point; for Linux in general, it is a common thing and I've tried many,
>> many of the solutions that others have found to work, all to no avail.  I
>> do not know how to get additional information on what is hanging as there
>> is really no context from which to proceed.
>> >
>> > I'm looking for suggestions on next steps to root cause this hang.
>> >
>> > Thanks and regards,
>> > Jim
>> 
>> Could you boot the machine with the stock kernel that works, then paste
>> the output of /proc/interrupts? This may help finding out which IRQ
>> controller might be involved in the issue.
>>
>
> Hello Philippe,
> Here is the output of /proc/interrupts from the stock 6.5.0 kernel.
>
> $ cat /proc/interrupts
>             CPU0       CPU1       CPU2       CPU3
>  134:          0          0          0          0  accel_3d-dev0       accel_3d_consumer0
>  136:          0          0          0          0  als-dev1       als_consumer1
>  142:          0          0          0          0  magn_3d-dev3       magn_3d_consumer3

Could you disable these features before retrying?

CONFIG_HID_SENSOR_MAGNETOMETER_3D
CONFIG_HID_SENSOR_ACCEL_3D
CONFIG_HID_SENSOR_ALS? (maybe.. there is a truckload of light sensors).

If the issue persists, disabling all IIO drivers could be a sensible
option to confirm that there may be an issue with some irqchip those
drivers depend on when it comes to dealing with Dovetail.

-- 
Philippe.