kernel-4.7 bug in Intel sound and/or ACPI

[Wim Osterholt]

L.S.
up to vanilla kernel-4.6.2 sound was working fine.
Switching to kernel-4.7.0-rc3 made sound disappear. No /dev/mixer etc.
There appears to be a bug in the Intel sound driver and/or ACPI driver.
Dmesg shows interesting lines like:
[   11.498592] ACPI: PCI Interrupt Link [LNKB] enabled at IRQ 7
[   11.498605] PCI: setting IRQ 7 as level-triggered
[   11.543903] parport0: PC-style at 0x378 (0x778), irq 7 [PCSPP,TRISTATE,EPP]
[   12.757735] genirq: Flags mismatch irq 7. 00000080 (snd_intel8x0m) vs. 00000000 (parport0)
[   12.757751] snd_intel8x0m 0000:00:1f.6: unable to grab IRQ 7
[   12.757875] snd_intel8x0m: probe of 0000:00:1f.6 failed with error -16
[   12.900171] genirq: Flags mismatch irq 7. 00000080 (snd_intel8x0) vs. 00000000 (parport0)
[   12.900189] snd_intel8x0 0000:00:1f.5: unable to grab IRQ 7
[   12.900389] snd_intel8x0: probe of 0000:00:1f.5 failed with error -16
[   12.922554] genirq: Flags mismatch irq 7. 00000080 (ipw2200) vs. 00000000 (parport0)
[   12.922559] ipw2200: Error allocating IRQ 7

If I boot kernel-4.7.0-rc3 with acpi=off  then sound is back!

If you need the full dmesg outputs then please get them here:
http://webserver.djo.tudelft.nl/dmesg460+ACPI
http://webserver.djo.tudelft.nl/dmesg473+ACPI
http://webserver.djo.tudelft.nl/dmesg473noACPI
(with excuses for the silly hostname which is out of our control)

Regards, Wim.


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