Document ACPI tunable hw.acpi.serialize_methods.

Also reorder tunables.

Approved by:	njl
MFC after:	1 week

1 files changed, 10 insertions, 4 deletions

diff --git a/share/man/man4/acpi.4 b/share/man/man4/acpi.4
index f2dcf0a..de6611b 100644
--- a/share/man/man4/acpi.4
+++ b/share/man/man4/acpi.4
@@ -357,10 +357,6 @@ BIOS, you can set this to 0 to re-enable ACPI for testing.
 Delay in milliseconds to wait for the EC to respond.
 Try increasing this number if you get the error
 .Er AE_NO_HARDWARE_RESPONSE .
-.It Va hw.acpi.reset_video
-Enables calling the VESA reset BIOS vector on the resume path.
-Some graphic chips have problems such as LCD white-out after resume.
-Try setting this to 0 if this causes problems for you.
 .It Va hw.acpi.osname
 Some systems' ASL may have problems because they look for names
 of Microsoft operating systems.
@@ -370,6 +366,16 @@ object from its default of
 .Qq Li FreeBSD .
 .It Va hw.acpi.pci.link.%d.%d.%d.irq
 Override the interrupt to use.
+.It Va hw.acpi.reset_video
+Enables calling the VESA reset BIOS vector on the resume path.
+Some graphic chips have problems such as LCD white-out after resume.
+Try setting this to 0 if this causes problems for you.
+.It Va hw.acpi.serialize_methods
+Allow override of whether methods execute in parallel or not.
+Enable this for serial behavior, which fixes "AE_ALREADY_EXISTS" errors for 
+AML that really can't handle parallel method execution.
+It is off by default since this breaks recursive methods and some IBMs use 
+such code.
 .It Va hw.acpi.verbose
 Turn on verbose debugging information about what ACPI is doing.
 .El