Outstanding ACPI issues for 5.1-RELEASE

The current state of FreeBSD ACPI is that the Intel 0228 dist was imported
along with a one-line fix to hwregs.c that solves power-off problems.

Here is a list of the current problems.  We would like to fix as many as
possible before the release.  If anyone has time to tackle these issues,
please let me know.  The reporters listed below should open a PR and send
me the number as I do not want to replicate GNATS in email.

--------------------------------------------------------------
Problem:  acpi_thermal causes a panic
Reporter: ru_at_freebsd.org
Information:
This looks like referencing a freed or uninitialized data member.

The below was produces with the latest 0228 ACPI diff in-tree, and acpi
device compiled directly into a kernel.  Loading it as a module gave me
some lines offset in the source file, and the faulting address was
0xdeadc0de.

The box.* files and "pciconf -l" output are available at:

        http://people.freebsd.org/~ru/acpi_thermal.panic.bz2

: #11 0xc02d5968 in calltrap () at {standard input}:96
: #12 0xc013c0fd in AcpiGetHandle (Parent=0xbffff, Pathname=0xc030d14e "_PS0",
:     RetHandle=0xc8761c2c) at /usr/src/sys/contrib/dev/acpica/nsxfname.c:177
: #13 0xc0153f83 in acpi_pwr_switch_consumer (consumer=0x0, state=0)
:     at /usr/src/sys/dev/acpica/acpi_powerres.c:359
: #14 0xc0155818 in acpi_tz_switch_cooler_on (obj=0xc189c9d0, arg=0xc1878300)
:     at /usr/src/sys/dev/acpica/acpi_thermal.c:588
: #15 0xc014ba8d in acpi_ForeachPackageObject (pkg=0xc1878300,
:     func=0xc01557e0 <acpi_tz_switch_cooler_on>, arg=0xc1878300)
:     at /usr/src/sys/dev/acpica/acpi.c:1186
: #16 0xc01555fb in acpi_tz_monitor (sc=0xc189c9d0)
:     at /usr/src/sys/dev/acpica/acpi_thermal.c:462
: #17 0xc0155b66 in acpi_tz_timeout (sc=0xc1878300)
:     at /usr/src/sys/dev/acpica/acpi_thermal.c:741
: #18 0xc0155d46 in acpi_tz_thread (arg=0x0)
:     at /usr/src/sys/dev/acpica/acpi_thermal.c:821

--------------------------------------------------------------
Problem: Uninstalling multiple SSDT tables
Reporter: Marcel <marcel_at_freebsd.org>

The HP rx2600 machines (ia64) have multiple SSDT tables. These
tables get nicely linked together. The first table descriptor
is static, the following table descriptors are allocated. When
shutting down the machine, these tables (and descriptors) will
get uninstalled. This however contains a bug: the ListHead is
removed first and since (head->next != head->prev) when more
than one instance of a table exists, it is not identified as
the list head and thus is being deallocated.

A tested patch is attached first. A minimal (untested) patch
is attached second. I like the second for it's simplicity.
Both patches try to fix the same problem: deallocation (freeing)
memory that was not previously allocated.

[Patch available, email me for it]

--------------------------------------------------------------
Problem: UtAllocate zero bytes warnings
Reporter: Warner Losh <imp_at_bsdimp.com>
Additional reporters: Thorsten Greiner <thorsten.greiner_at_consol.de>

     ACPI-0293: *** Warning: Buffer created with zero length in AML
         -0166: *** Error: UtAllocate: Attempt to allocate zero bytes

DSDT and other info is here:
    http://www.stethojupi.de/acpi.tar.bz2

--------------------------------------------------------------
Problem:  AML_BUFFER_LIMIT errors on boot
Reporter: rwatson_at_freebsd.org
Information:
Tons of errors printed at boot.
    ACPI-1287: *** Error: Method execution failed [\\_SB_.PSRS] (Node 0xc0b77ca0), AE_AML_BUFFER_LIMIT
    ACPI-1287: *** Error: Method execution failed [\\_SB_.PIIF._SRS] (Node 0xc188cc80), AE_AML_BUFFER_LIMIT
    ACPI-1287: *** Error: Method execution failed [\\_SB_.PSRS] (Node 0xc0b77ca0), AE_AML_BUFFER_LIMIT
    ACPI-1287: *** Error: Method execution failed [\\_SB_.PIIF._SRS] (Node 0xc188cc80), AE_AML_BUFFER_LIMIT
    ACPI-1287: *** Error: Method execution failed [\\_SB_.PSRS] (Node 0xc0b77ca0), AE_AML_BUFFER_LIMIT
    ACPI-1287: *** Error: Method execution failed [\\_SB_.PIIF._SRS] (Node 0xc188cc80), AE_AML_BUFFER_LIMIT
    ACPI-1287: *** Error: Method execution failed [\\_SB_.PSRS] (Node 0xc0b77ca0), AE_AML_BUFFER_LIMIT
    ACPI-1287: *** Error: Method execution failed [\\_SB_.PIIF._SRS] (Node 0xc188cc80), AE_AML_BUFFER_LIMIT
    ACPI-1287: *** Error: Method execution failed [\\_SB_.PSRS] (Node 0xc0b77ca0), AE_AML_BUFFER_LIMIT