acpi: cpuhp: spec: fix 'Command data' description

Correct returned value description in case 'Command field' == 0x0,
it's not PXM but CPU selector value with pending event

In addition describe 0 blanket value in case of not supported
'Command field' value.

Signed-off-by: Igor Mammedov <imammedo@redhat.com>
Reviewed-by: Laszlo Ersek <lersek@redhat.com>
Message-Id: <1575896942-331151-6-git-send-email-imammedo@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

diff --git a/docs/specs/acpi_cpu_hotplug.txt b/docs/specs/acpi_cpu_hotplug.txt
index 4e65286..d510872 100644 (file)
--- a/docs/specs/acpi_cpu_hotplug.txt
+++ b/docs/specs/acpi_cpu_hotplug.txt
@@ -56,9 +56,8 @@ read access:
            3-7: reserved and should be ignored by OSPM
     [0x5-0x7] reserved
     [0x8] Command data: (DWORD access)
-          in case of error or unsupported command reads is 0xFFFFFFFF
-          current 'Command field' value:
-              0: returns PXM value corresponding to device
+          contains 0 unless value last stored in 'Command field' is one of:
+              0: contains 'CPU selector' value of a CPU with pending event[s]
 
 write access:
     offset:
@@ -81,9 +80,9 @@ write access:
           value:
             0: selects a CPU device with inserting/removing events and
                following reads from 'Command data' register return
-               selected CPU (CPU selector value). If no CPU with events
-               found, the current CPU selector doesn't change and
-               corresponding insert/remove event flags are not set.
+               selected CPU ('CPU selector' value).
+               If no CPU with events found, the current 'CPU selector' doesn't
+               change and corresponding insert/remove event flags are not modified.
             1: following writes to 'Command data' register set OST event
                register in QEMU
             2: following writes to 'Command data' register set OST status