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acpi_cpu_notify: disable acpi_cpu_idle while updating C-state data

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... to avoid any races or inconsistencies.
This should fix a regression introduced in r243404.

Also, remove a stale comment that has not been true for quite a while
now.

Pointyhat to:	avg
Teested by:	trociny, emaste, dumbbell (earlier version)
MFC after:	 1 week
This commit is contained in:
avg 2012-12-01 18:06:05 +00:00
parent 2574e6f8e5
commit e670629b6a
1 changed files with 15 additions and 7 deletions
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22
sys/dev/acpica/acpi_cpu.c
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@ -973,9 +973,9 @@ acpi_cpu_idle()
return;
}
/* If disabled, return immediately. */
/* If disabled, take the safe path. */
if (is_idle_disabled(sc)) {
ACPI_ENABLE_IRQS();
acpi_cpu_c1();
return;
}
@ -1081,23 +1081,31 @@ acpi_cpu_idle()
/*
* Re-evaluate the _CST object when we are notified that it changed.
*
* XXX Re-evaluation disabled until locking is done.
*/
static void
acpi_cpu_notify(ACPI_HANDLE h, UINT32 notify, void *context)
{
struct acpi_cpu_softc *sc = (struct acpi_cpu_softc *)context;
if (notify != ACPI_NOTIFY_CX_STATES)
return;
/*
* C-state data for target CPU is going to be in flux while we execute
* acpi_cpu_cx_cst, so disable entering acpi_cpu_idle.
* Also, it may happen that multiple ACPI taskqueues may concurrently
* execute notifications for the same CPU. ACPI_SERIAL is used to
* protect against that.
*/
ACPI_SERIAL_BEGIN(cpu);
disable_idle(sc);
/* Update the list of Cx states. */
acpi_cpu_cx_cst(sc);
acpi_cpu_cx_list(sc);
ACPI_SERIAL_BEGIN(cpu);
acpi_cpu_set_cx_lowest(sc);
enable_idle(sc);
ACPI_SERIAL_END(cpu);
acpi_UserNotify("PROCESSOR", sc->cpu_handle, notify);