Re: hid-related 5.2-rc1 boot hang

From: Hans de Goede
Date: Mon Jun 03 2019 - 05:36:01 EST


Hi,

On 03-06-19 11:11, Hans de Goede wrote:
Hi,

On 01-06-19 00:15, Jiri Kosina wrote:
On Thu, 30 May 2019, Dave Hansen wrote:

On 5/29/19 2:17 AM, Hans de Goede wrote:
...
Dave, can you try building your initrd without the hid-logitech-dj module
included in the initrd?

I did this on a vanilla 5.2-rc2 kernel (without the reverts) and still
experienced the boot hang while the device was inserted.

Also can you check if your modprobe is provided by module-init-tools
or by kmod ?

$ dpkg -S `which modprobe`
kmod: /sbin/modprobe

Benjamin, Hans, are you looking into this?

Not really, I cannot reproduce the request_module problem. I was hoping some
of the info from Dave would help to pinpoint it, but it does not :|

If not, I think we should start reverting (at least the request_module()
changes

I agree we need to do something about the request_module changes.

I myself was thinking about somehow making them conditional, e.g. we
could add a (temporary) module option defaulting to false for this
while we investigate further.

I'm afraid that if we just revert we will never find the root cause and then
we will be stuck with the suboptimal behavior of first the generic hid driver
binding followed by a unbind + bind of the new driver shortly afterwards,
which also leads to a ton of udev events being fired to userspace (well I
guess this does make for a good stress test of the userspace hotplug code).

Quick update, we have another report of module-loading related problems
which are likely related:

https://bugzilla.kernel.org/show_bug.cgi?id=203741

In this case there is no hang, instead there is a 1 to 3 minute delay.

Regards,

Hans