Bug 50521

Summary: nouveau_acpi call _DSM with wrong parameter
Product: Drivers Reporter: Alex Williamson (alex.williamson)
Component: Video(DRI - non Intel)Assignee: drivers_video-dri
Status: REOPENED ---    
Severity: normal CC: alan, daniel
Priority: P1    
Hardware: All   
OS: Linux   
Kernel Version: 2.6.38 Subsystem:
Regression: No Bisected commit-id:

Description Alex Williamson 2012-11-13 15:17:44 UTC 
Cloning for nouveau

+++ This bug was initially created as a clone of Bug #32602 +++

Both drivers/gpu/drm/i915/intel_acpi.c and drivers/gpu/drm/nouveau/nouveau_acpi.c call _DSM methods with parameters of _DSM(Buffer, Integer, Integer, Integer).  The ACPI spec defines the parameters to be _DSM(Buffer, Integer, Integer, Package).  On a UL30VT, the AML preforms operations on Arg3 which are not valid for an Integer data type, resulting in ACPI faults.  Excerpt of DSDT:

Method (_DSM, 4, NotSerialized)
{
    If (LEqual (Arg0, Buffer (0x10)
            {
                /* 0000 */    0xA0, 0xA0, 0x95, 0x9D, 0x60, 0x00, 0x48, 0x4D,
                /* 0008 */    0xB3, 0x4D, 0x7E, 0x5F, 0xEA, 0x12, 0x9F, 0xD4
            }))
    {
        Store (Zero, Local0)
        Store (ShiftLeft (DerefOf (Index (Arg3, 0x03)), 0x18), Local0)
        Add (ShiftLeft (DerefOf (Index (Arg3, 0x02)), 0x10), Local0, Local0)
        Add (ShiftLeft (DerefOf (Index (Arg3, One)), 0x08), Local0, Local0)
        Add (ShiftLeft (DerefOf (Index (Arg3, Zero)), Zero), Local0, Local0)
        ...

The Index operation is only valid on a Buffer, String, or Package, which is perfectly reasonable given the definition of the _DSM call.
Comment 1 Yill Din 2013-12-28 07:14:18 UTC 
Why was this closed as "RESOLVED"? The code is still present in the kernel, and it still causes errors. My _DSM looks identically to the above. (Asus X73SV)
Comment 2 Alan 2013-12-28 12:07:55 UTC 
It was fixed on August 1st. If you have an older kernel you'll need to update

commit 6d5c2d8ca3c15a191a8078316e547c1f4e5ad6eb
Comment 3 Alan 2013-12-28 12:10:07 UTC 
Ah .. sorry only Intel was fixed.. Nouveau folks must be slacking ;-)