Author: avg
Date: Mon Sep 13 09:51:24 2010
New Revision: 212549
URL: http://svn.freebsd.org/changeset/base/212549

Log:
  acpi_cpu: do not apply P_LVLx_LAT rules to latencies returned by _CST
  
  ACPI specification sates that if P_LVL2_LAT > 100, then a system doesn't
  support C2; if P_LVL3_LAT > 1000, then C3 is not supported.
  But there are no such rules for Cx state data returned by _CST.  If a
  state is not supported it should not be included into the return
  package.  In other words, any latency value returned by _CST is valid,
  it's up to the OS and/or user to decide whether to use it.
  
  Submitted by: nork
  Suggested by: mav
  MFC after:    1 week

Modified:
  head/sys/dev/acpica/acpi_cpu.c

Modified: head/sys/dev/acpica/acpi_cpu.c
==============================================================================
--- head/sys/dev/acpica/acpi_cpu.c      Mon Sep 13 09:23:38 2010        
(r212548)
+++ head/sys/dev/acpica/acpi_cpu.c      Mon Sep 13 09:51:24 2010        
(r212549)
@@ -690,19 +690,11 @@ acpi_cpu_cx_cst(struct acpi_cpu_softc *s
            sc->cpu_cx_count++;
            continue;
        case ACPI_STATE_C2:
-           if (cx_ptr->trans_lat > 100) {
-               ACPI_DEBUG_PRINT((ACPI_DB_INFO,
-                                "acpi_cpu%d: C2[%d] not available.\n",
-                                device_get_unit(sc->cpu_dev), i));
-               continue;
-           }
            sc->cpu_non_c3 = i;
            break;
        case ACPI_STATE_C3:
        default:
-           if (cx_ptr->trans_lat > 1000 ||
-               (cpu_quirks & CPU_QUIRK_NO_C3) != 0) {
-
+           if ((cpu_quirks & CPU_QUIRK_NO_C3) != 0) {
                ACPI_DEBUG_PRINT((ACPI_DB_INFO,
                                 "acpi_cpu%d: C3[%d] not available.\n",
                                 device_get_unit(sc->cpu_dev), i));
_______________________________________________
svn-src-head@freebsd.org mailing list
http://lists.freebsd.org/mailman/listinfo/svn-src-head
To unsubscribe, send any mail to "svn-src-head-unsubscr...@freebsd.org"

Reply via email to