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ACPI / PM: Make __acpi_bus_get_power() cover D3cold correctly 

After recent changes of the ACPI device power states definitions, if
power resources are not used for the device's power management, the
state returned by __acpi_bus_get_power() cannot exceed D3hot, because
the return values of _PSC are 0 through 3.  However, if the _PR3
method is not present for the device and _PS3 returns 3, we have to
assume that the device is in D3cold, so the value returned by
__acpi_bus_get_power() in that case should be 4.

Similarly, acpi_power_get_inferred_state() should take the power
resources for the D3hot state into account in general, so that it
can return 3 if those resources are "on" or 4 (D3cold) otherwise.

Fix the the above two issues and make sure that if both _PSC and
_PR3 are present for the device, the power resources listed by _PR3
will be used to determine if the number 3 returned by _PSC is meant
to represent D3cold or D3hot.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
hifive-unleashed-5.1
Rafael J. Wysocki 2012-05-20 13:58:00 +02:00
parent 63a1a765df
commit 38c92fff98
2 changed files with 30 additions and 23 deletions
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51
drivers/acpi/bus.c
View File

@ -202,37 +202,44 @@ static const char *state_string(int state)
static int __acpi_bus_get_power(struct acpi_device *device, int *state)
{
int result = 0;
acpi_status status = 0;
unsigned long long psc = 0;
int result = ACPI_STATE_UNKNOWN;
if (!device || !state)
return -EINVAL;
*state = ACPI_STATE_UNKNOWN;
if (device->flags.power_manageable) {
/*
* Get the device's power state either directly (via _PSC) or
* indirectly (via power resources).
*/
if (device->power.flags.power_resources) {
result = acpi_power_get_inferred_state(device, state);
if (result)
return result;
} else if (device->power.flags.explicit_get) {
status = acpi_evaluate_integer(device->handle, "_PSC",
NULL, &psc);
if (ACPI_FAILURE(status))
return -ENODEV;
*state = (int)psc;
}
} else {
if (!device->flags.power_manageable) {
/* TBD: Non-recursive algorithm for walking up hierarchy. */
*state = device->parent ?
device->parent->power.state : ACPI_STATE_D0;
goto out;
}
/*
* Get the device's power state either directly (via _PSC) or
* indirectly (via power resources).
*/
if (device->power.flags.explicit_get) {
unsigned long long psc;
acpi_status status = acpi_evaluate_integer(device->handle,
"_PSC", NULL, &psc);
if (ACPI_FAILURE(status))
return -ENODEV;
result = psc;
}
/* The test below covers ACPI_STATE_UNKNOWN too. */
if (result <= ACPI_STATE_D2) {
; /* Do nothing. */
} else if (device->power.flags.power_resources) {
int error = acpi_power_get_inferred_state(device, &result);
if (error)
return error;
} else if (result == ACPI_STATE_D3_HOT) {
result = ACPI_STATE_D3;
}
*state = result;
out:
ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Device [%s] power state is %s\n",
device->pnp.bus_id, state_string(*state)));

2
drivers/acpi/power.c
View File

@ -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_HOT; i++) {
for (i = ACPI_STATE_D0; i <= ACPI_STATE_D3_HOT; i++) {
list = &device->power.states[i].resources;
if (list->count < 1)
continue;