No interrupts for uspace on real hardware when SMP enabled

[Jiri Svoboda]

As of mainline,1487, no USB devices work for me at all on bare metal (either Sony Vaio with UHCI or AMD workstation with OHCI). If I plug in a device, nothing seems to happen. The device does not power on and it does not appear in the device tree, I also don't see anything in the USB logs. Tried this with several different devices (keyboard, mouse, mass storage).

[Martin Decky]

Is it actually related to mainline,1487? I don't see any USB-related changes in that changeset. Can you bisect the history where the breakage happens?

[Jiri Svoboda]

This is the revision I tested, I did not claim it was broken by this changeset. I will search for the commit that broke it when get the chance.

[Jiri Svoboda]

After some tedious bisecting with no result I finally remembered about the problem with interrupts on SMP. When I disable SMP support, USB works just fine as of latest mainline (mainline,1490). I thought interrupts on ia32/SMP were supposed to be working now, no? If not, it's quite a serious issue.

[Martin Decky]

AFAIK the uspace APIC driver is still a bit simplified. It can handle basic setups (such as in QEMU), but it is likely to fail on more complex setups on real hardware.

There is a ticket for that (#387). It would be also great to finally integrate the interrupt controller drivers into the DDF, the current solution is still just a hack.

[Jakub Jermář]

It may be a good idea to look into /proc/iomem on Linux and see if the IO APIC and the local APICS are at the expected IO base addresses or not (0xfec00000 for IO APIC). If they are not, implementing #387 may actually help.

Since no one complained and SMP started to work for MartinS after fixing physmem_map(), #387 lost some of its priority.

[Jiri Svoboda]

Snippet from my /proc/iomem:

fec00000-ffffffff : reserved

fec00000-fec003ff : IOAPIC 0
fed00000-fed003ff : HPET 0
fee00000-fee00fff : Local APIC

fee00400-fee00fff : pnp 00:02

fff80000-fffeffff : pnp 00:0d
ffff0000-ffffffff : pnp 00:0d

100000000-12fffffff : System RAM

[Jakub Jermář]

orome_:

as to what causes usb to not work, I think it's because apic reports interrupts enabled when they are not, otherwise both HC drviers should fall back to polling.

[Jakub Jermář]

Jiri, could you please verify that interrupts are working properly for kernel in SMP on your machine by completely deactivating uspace so that you'll be left with only kconsole? That would be really helpful.

[Jakub Jermář]

I am inclined towards moving this to the next release as this is probably not a regression. Even if it is a regression, it is a known regression.