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authorLin Ming <ming.m.lin@intel.com>2012-04-23 09:03:49 +0800
committerLen Brown <len.brown@intel.com>2012-05-05 01:19:52 -0400
commit1cc0c998fdf2cb665d625fb565a0d6db5c81c639 (patch)
tree2768315b4d2217ea16082947bf995edfc40d5faf /drivers/acpi
parentec612fcf43e09f5e05d37baf4d3f138b3fcc2f3d (diff)
ACPI: Fix D3hot v D3cold confusion
Before this patch, ACPI_STATE_D3 incorrectly referenced D3hot in some places, but D3cold in other places. After this patch, ACPI_STATE_D3 always means ACPI_STATE_D3_COLD; and all references to D3hot use ACPI_STATE_D3_HOT. ACPI's _PR3 method is used to enter both D3hot and D3cold states. What distinguishes D3hot from D3cold is the presence _PR3 (Power Resources for D3hot) If these resources are all ON, then the state is D3hot. If _PR3 is not present, or all _PR0 resources for the devices are OFF, then the state is D3cold. This patch applies after Linux-3.4-rc1. A future syntax cleanup may remove ACPI_STATE_D3 to emphasize that it always means ACPI_STATE_D3_COLD. Signed-off-by: Lin Ming <ming.m.lin@intel.com> Acked-by: Rafael J. Wysocki <rjw@sisk.pl> Reviewed-by: Aaron Lu <aaron.lu@amd.com> Signed-off-by: Len Brown <len.brown@intel.com>
Diffstat (limited to 'drivers/acpi')
-rw-r--r--drivers/acpi/power.c2
-rw-r--r--drivers/acpi/scan.c17
2 files changed, 8 insertions, 11 deletions
diff --git a/drivers/acpi/power.c b/drivers/acpi/power.c
index 7049a7d27c4..330bb4d7585 100644
--- a/drivers/acpi/power.c
+++ b/drivers/acpi/power.c
@@ -631,7 +631,7 @@ int acpi_power_get_inferred_state(struct acpi_device *device, int *state)
* We know a device's inferred power state when all the resources
* required for a given D-state are 'on'.
*/
- for (i = ACPI_STATE_D0; i < ACPI_STATE_D3; i++) {
+ for (i = ACPI_STATE_D0; i < ACPI_STATE_D3_HOT; i++) {
list = &device->power.states[i].resources;
if (list->count < 1)
continue;
diff --git a/drivers/acpi/scan.c b/drivers/acpi/scan.c
index 767e2dcb961..7417267e88f 100644
--- a/drivers/acpi/scan.c
+++ b/drivers/acpi/scan.c
@@ -869,7 +869,7 @@ static int acpi_bus_get_power_flags(struct acpi_device *device)
/*
* Enumerate supported power management states
*/
- for (i = ACPI_STATE_D0; i <= ACPI_STATE_D3; i++) {
+ for (i = ACPI_STATE_D0; i <= ACPI_STATE_D3_HOT; i++) {
struct acpi_device_power_state *ps = &device->power.states[i];
char object_name[5] = { '_', 'P', 'R', '0' + i, '\0' };
@@ -884,21 +884,18 @@ static int acpi_bus_get_power_flags(struct acpi_device *device)
acpi_bus_add_power_resource(ps->resources.handles[j]);
}
- /* The exist of _PR3 indicates D3Cold support */
- if (i == ACPI_STATE_D3) {
- status = acpi_get_handle(device->handle, object_name, &handle);
- if (ACPI_SUCCESS(status))
- device->power.states[ACPI_STATE_D3_COLD].flags.valid = 1;
- }
-
/* Evaluate "_PSx" to see if we can do explicit sets */
object_name[2] = 'S';
status = acpi_get_handle(device->handle, object_name, &handle);
if (ACPI_SUCCESS(status))
ps->flags.explicit_set = 1;
- /* State is valid if we have some power control */
- if (ps->resources.count || ps->flags.explicit_set)
+ /*
+ * State is valid if there are means to put the device into it.
+ * D3hot is only valid if _PR3 present.
+ */
+ if (ps->resources.count ||
+ (ps->flags.explicit_set && i < ACPI_STATE_D3_HOT))
ps->flags.valid = 1;
ps->power = -1; /* Unknown - driver assigned */