[LAU] HDA-Intel headphone interrupt locking up kernel
ken at restivo.org
Thu Jul 30 17:12:20 EDT 2009
Found a really fun one.
Plug in or unplug my headphone, and my computer locks up. This is with hda-intel with msi-enable.
Apparently the headphone plugging/unplugging generates an interrupt. I am using msi-enable. When the thing sleeps and comes back from sleep, sometimes the kernel, the BIOS, ACPI, and the snd-hda-intel driver aren't in agreement as to what IRQ the thing is on. Sometimes I end up with this:
16: 1321610 IO-APIC-fasteoi uhci_hcd:usb5, i915 at pci:0000:00:02.0, HDA Intel
218: 2 none-edge
219: 3063329 none-edge
I've got RT kernel, and the IRQ-219 is set to highest priority.
1673 FF 85 - 125 0.2 S< IRQ-219
Now, if I am careless enough to generate an interrupt by plugging in the headphone, the system will lock-up, hard-core.
I can avoid the problem by whacking the snd-hda-intel driver with a ball-peen hammer until it decides to go back onto the correct IRQ again:
sudo modprobe -r snd-hda-intel
sudo modprobe snd-hda-intel
16: 1337804 IO-APIC-fasteoi uhci_hcd:usb5, i915 at pci:0000:00:02.0
219: 3063459 PCI-MSI-edge HDA Intel
And no problem.
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