It's not a problem, but the syntax used here is technically 'legacy' vs
the newer ASL 2.0 syntax.
From https://acpica.org/sites/acpica/files/ASL2.0Overview.pdf
Version 6.0 of the Advanced Configuration and Power interface (ACPI)
specification introduced
support for standard symbolic operators and expressions in the ACPI
Source Language (ASL).
These changes are known as ASL 2.0 and are detailed in chapter 19 of the
ACPI specification.
This document intends to increase visibility and further explain the
benefits and implementation
of these changes.
Legacy ASL
As more developers begin working with ACPI, the limitations of the ASL
language itself have
become more apparent. The main mathematical and logical operators of ASL
are expressed in
Polish notation, which places operators to the left of operands, as
shown in the examples below:
Add (X, Y, Z)
LEqual (X, Y)
Building complex expressions with this notation can make ASL code
practically unreadable by
humans. Even experienced BIOS engineers can find ASL expressions
difficult to parse, while
developers new to the language might find ASL to be inaccessible
compared to languages that
use a more common notation.
ASL 2.0
Fortunately version 6.0 of the ACPI specification has introduced
standard symbolic operators
and infix expressions for ASL that are similar to those used in C and
other common algebraic
languages. The following examples show how the legacy ASL syntax above
is expressed in
ASL 2.0:
Z = X + Y
If (X == Y)
The ASL 2.0 operator precedence and associativity rules are identical to
the C language.These
new symbolic operators are backwards compatible with existing legacy ASL
operators, and are
implemented with only minor changes to the ASL compiler and AML
disassembler.
These changes to the ASL language are significant enough to warrant
changing the name of the
language to ASL 2.0, as compared to legacy ASL.
--
Rebecca Cran
On 1/12/23 9:25 PM, Nhi Pham via groups.io wrote:
+ Method (_OSC, 4) {
+
+ //
+ // Look for the PCI Host Bridge Interface UUID.
+ // Section 6.2.10.3
+ //
+
+ //
+ // Create DWord-adressable fields from the Capabilities Buffer
+ // Create CDW1 outside the test as it's used in the else clause.
+ //
+
+ CreateDWordField (Arg3, 0, CDW1)
+ If (LEqual (Arg0, ToUUID("33DB4D5B-1FF7-401C-9657-7441C03DD766"))) {
+
+ CreateDWordField (Arg3, 4, CDW2)
+ CreateDWordField (Arg3, 8, CDW3)
+
+ //
+ // Save Capabilities DWord 2 & 3
+ //
+
+ Store (CDW2, SUPP)
+ Store (CDW3, CTRL)
+
+ //
+ // Only allow native hot plug control if OS supports:
+ // ASPM
+ // Clock PM
+ // MSI/MSI-X
+ //
+
+ If (LNotEqual (And (SUPP, 0x16), 0x16)) {
+
+ //
+ // Mask bit 0 (and undefined bits)
+ //
+
+ And (CTRL, 0x1E, CTRL)
+ }
+
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