Segher Boessenkool segher at kernel.crashing.org
Tue Apr 24 03:39:23 EST 2007

> Rename MPIC_BROKEN_U3 to something a little more descriptive. Its
> effect is to enable support for HT irqs behind the PCI-X/HT bridge on
> U3/U4 (aka. CPC9x5) parts.

Not quite.  It's a workaround for the problem that
the U3/U4 HT interrupt interface doesn't send ACKs
for interrupts that require them ("level" interrupts).
It does this by setting the ACK bit in HT APIC config
space every time an interrupt from such a source happens.

This doesn't affect PCI bridges only.

The name change looks good though :-)


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