Date: Fri, 16 Apr 2004 12:46:30 -0700 (PDT) From: John Baldwin <jhb@FreeBSD.org> To: src-committers@FreeBSD.org, cvs-src@FreeBSD.org, cvs-all@FreeBSD.org Subject: cvs commit: src/sys/i386/acpica madt.c Message-ID: <200404161946.i3GJkUoo029614@repoman.freebsd.org>
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jhb 2004/04/16 12:46:30 PDT
FreeBSD src repository
Modified files:
sys/i386/acpica madt.c
Log:
Revert part of the "BIOS brain damage" from rev 1.10. It seems that
different BIOSs use the same exact settings to mean two very different and
incompatible things for the SCI. Thus, if the SCI is remapped to a PCI
interrupt, we now trust the trigger/polarity that the MADT provides by
default. However, the SCI can be forced to level/lo as 1.10 did by setting
the tunable "hw.acpi.force_sci_lo" to a non-zero value from the loader.
Thus, if rev 1.10 caused an interrupt storm, it should nwo fix your
machine. If rev 1.10 fixed an interrupt storm on your machine, you
probably need to set the aforementioned tunable in /boot/loader.conf to
prevent the interrupt storm.
The more general problem of getting the SCI's trigger/polarity programmed
"correctly" (for some value of correctly meaning several workarounds for
broken BIOSs and inconsistent "implementations" of the ACPI standard) is
going to require more work, but this band-aid should improve the current
situation somewhat.
Requested by: njl
Revision Changes Path
1.11 +5 -4 src/sys/i386/acpica/madt.c
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