[Bugme-new] [Bug 11421] New: HP dv5z DSDT is broken

[bugme-daemon at bugzilla.kernel.org]

http://bugzilla.kernel.org/show_bug.cgi?id=11421

           Summary: HP dv5z DSDT is broken
           Product: ACPI
           Version: 2.5
     KernelVersion: 2.6.26.3
          Platform: All
        OS/Version: Linux
              Tree: Mainline
            Status: NEW
          Severity: normal
          Priority: P1
         Component: BIOS
        AssignedTo: acpi_bios at kernel-bugs.osdl.org
        ReportedBy: hyc at highlandsun.com


Latest working kernel version:
Earliest failing kernel version: any
Distribution: Ubuntu
Hardware Environment:
Software Environment:
Problem Description:
/proc/acpi/thermal_zone is empty after booting. During boot this message is
seen:
[    5.895095] ACPI: ACPI0007:00 is registered as cooling_device0
[    5.895107] ACPI: Processor [CPU0] (supports 8 throttling states)
[    5.895307] ACPI: ACPI0007:01 is registered as cooling_device1
[    5.899969] ACPI Exception (thermal-0377): AE_OK, No or invalid critical
threshold [20080321]

The DSDT contains checks for Windows 6; in the _TZ scope there are two handlers
defined thus:
            Method (_HOT, 0, Serialized)
            {
                If (LEqual (TPOS, 0x40))
                {
                    Return (Add (0x0AAC, Multiply (TPC, 0x0A)))
                }
            }

            Method (_CRT, 0, Serialized)
            {
                If (LLess (TPOS, 0x40))
                {
                    Return (Add (0x0AAC, Multiply (TPC, 0x0A)))
                }
            }

If Windows 6 is detected, TPOS = 0x41. For Linux it defaults to 0x80. In that
case these two handlers exit without any return value, which is illegal.
Commenting out the If comparisons and recompiling the DSDT allows thermal
monitoring to work.

There are several other checks of the OS value in this DSDT, most of them
appear to be related to buttons controlling the VGA display mode (e.g.
CRT->LCD->TV). I've commented those checks out in my DSDT now too, but haven't
seen any visible effect.

Steps to reproduce:
Just boot any ACPI-enabled Linux kernel and observe the error message, and note
the empty /proc/acpi/thermal_zone directory.


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