Arch Linux

mich41

Member

Registered: 2012-06-22

Posts: 796

Re: USB Device Freezes my boot process

Mega-IRQ problems means that different IRQ #s (e.g. 10, 11) say "no one answered." In other words, part of the processor is turned off, if I'm understanding correctly.

No, "nobody cared" means that interrupt was correctly received by no driver expected it. So it's more like some device generates interrupts when it shouldn't or Linux doesn't know where interrupts are coming from because data provided by BIOS are fubar. Probably the latter because there are issues with more than one IRQ.

As for the main problem, I really think it's caused by lockup of some BIOS code called by the kernel. Since there are no updates available, it's time to get over it and consider low-tech solutions like PS/2 keyboard and no legacy usb or installing one of those PCI USB controllers and moving the offending device there.

EDIT:
As a last-ditch attempt, you may try noapic. Not perfect but better than acpi=off + irqpoll, although it probably won't help anyway.
Heck, or even clear or format this flash memory Maybe the BIOS actually cares about such things, who knows.

Last edited by mich41 (2015-12-17 13:26:47)

ohmysql

Member

Registered: 2015-03-13

Posts: 33

Re: USB Device Freezes my boot process

Frighteningly, nolapic or noapic with irqpoll seems to work (without irqpoll it seems to hang). I dunno what's worse, constantly plugging and unplugging this USB or turning off APIC or turning off ACPI. I will definitely try to get a PS/2 keyboard if I can! I think that's a good idea, so long as USB can be turned back on later in the boot process? Cuz I do need it.

mich41

Member

Registered: 2012-06-22

Posts: 796

Re: USB Device Freezes my boot process

Legacy USB is only about USB support in the BIOS. Disabling it simply means that BIOS will enable USB controllers, but will not use them for anything.

Now this mess makes me wonder if the IRQ issues would still persist if this dongle was disconnected, i.e. would it boot with pci=noacpi or with noapic but without irqpoll and without the dongle. But it's purely academic, I still wouldn't know how to fix it

ohmysql

Member

Registered: 2015-03-13

Posts: 33

Re: USB Device Freezes my boot process

Ah, perhaps so disabling legacy USB w/ a PS/2 keyboard is a good workaround

But perhaps your academic interests might help solve this though. Without the dongle, noapic works without irqpoll. But pci=noacpi fails both with and without irqpoll.

So maybe the best solution, crazy as it might sound, is to find some way for pci=noacpi to work. Is that making sense? I'm on my other computer but I can get you the dmesg if that seems promising.

EDIT: I can't figure out how to give you a dmesg from a failed boot (a previous boot).

Also, since we've identified that the problem happens somewhere in the ACPI process (including APIC), I will try all of these options and report back.

https://wiki.ubuntu.com/DebuggingACPI

EDIT 2:

Here are the results:

acpi=off crashed but acpi=off irqpoll worked but it's extreme.
acpi=ht worked.
pnpacpi=off hung until unplug but with irqpoll this worked.
just irqpoll worked much of the time but not always. That may be the least disruptive option.
acpi=noirq required me too unplug the dongle for it to work. In other words, it didn't work but it didn't crash.
pci=noacpi crashed.
noapic required me to unplug but noapic irqpoll did work.
nolapic worked.

I hope that  bit of debugging helps somewhere

EDIT 3: if you wanna see how deep this wormhole can go, see here...

https://wiki.ubuntu.com/Kernel/Referenc … cksAndTips

Last edited by ohmysql (2015-12-18 23:47:16)

mich41

Member

Registered: 2012-06-22

Posts: 796

Re: USB Device Freezes my boot process

OK, so it seems that generally irqpoll helps and the rest doesn't change much. I wonder if the less hardcore irqfixup would be enough.

Are you sure about acpi=ht? I see no such option in current kernel source, what version you are on? Does acpi=blah work equally well?

I don't know what to think about nolapic. BTW, I think it may disable all CPU cores besides one.

If you are not afraid of really dark voodoo, check if it unfreezes if you hit the power button few times or connect/disconnect some other USB2.0 device

ohmysql

Member

Registered: 2015-03-13

Posts: 33

Re: USB Device Freezes my boot process

Ok, I'll try irqfixup for a while and let you know.

I see acpi=ht here:

https://help.ubuntu.com/community/BootOptions

Though I have no idea how to tell if this option is possible in my current kernel. It did seem to work--it seems to mostly turn off ACPI. Which, by the way, of all those options, disabling ACPI always worked, so we do know, I think, where the source of the problem lies.

I will try acpi=blah at some point for the hell of it.

I see about nolapic! I had a feeling it was bad, but didn't think it was that bad.

And ok! I'll try what you said about power and USB devices. This is voodoo...

ohmysql

Member

Registered: 2015-03-13

Posts: 33

Re: USB Device Freezes my boot process

My experience is that irqpoll seems to be helpful more often than irqfixup, but this is hard to quantify since both work and fail sometimes. acpi=off on the other hand does seem to work every time.

acpi=blah froze whereas acpi=ht does seem to work every time.

Also, I tried your experiment about unplugging other USB devices while the thing was frozen and that seemed to do nothing. The power button didn't work either

mich41

Member

Registered: 2012-06-22

Posts: 796

Re: USB Device Freezes my boot process

Well, I thought that maybe ACPI/BIOS waits for some interrupts which get lost somehow and that artificially triggering few ACPI interrupts with power button could help, but if this does nothing then I have no idea what's going on.

ohmysql

Member

Registered: 2015-03-13

Posts: 33

Re: USB Device Freezes my boot process

Hmm, yeah, I've tried a few times, without a ton of luck. Maybe let's be in touch in a few weeks to see if we have any other ideas?

ohmysql

Member

Registered: 2015-03-13

Posts: 33

Re: USB Device Freezes my boot process

Well, in good news, with irqpoll this has rarely been a problem. I think I had to unplug the USB today for the first time in a while. I'll mark this as solved I guess, since it is close to solved... depending on the kernel!