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Merge branch 'acpi-pm' into linux-next 

* acpi-pm:
  ACPI / PM: Fix potential problem in acpi_device_get_power()
This commit is contained in:
Rafael J. Wysocki 2013-04-08 12:31:48 +02:00
parent 6912897d75 75eb2d13ac
commit 077f893bd9
1 changed files with 26 additions and 17 deletions
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43
drivers/acpi/device_pm.c
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@ -145,27 +145,36 @@ int acpi_device_get_power(struct acpi_device *device, int *state)
}
/*
* Get the device's power state either directly (via _PSC) or
* indirectly (via power resources).
* Get the device's power state from power resources settings and _PSC,
* if available.
*/
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) {
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;
}
if (device->power.flags.explicit_get) {
acpi_handle handle = device->handle;
unsigned long long psc;
acpi_status status;
status = acpi_evaluate_integer(handle, "_PSC", NULL, &psc);
if (ACPI_FAILURE(status))
return -ENODEV;
/*
* The power resources settings may indicate a power state
* shallower than the actual power state of the device.
*
* Moreover, on systems predating ACPI 4.0, if the device
* doesn't depend on any power resources and _PSC returns 3,
* that means "power off". We need to maintain compatibility
* with those systems.
*/
if (psc > result && psc < ACPI_STATE_D3_COLD)
result = psc;
else if (result == ACPI_STATE_UNKNOWN)
result = psc > ACPI_STATE_D2 ? ACPI_STATE_D3_COLD : psc;
}
/*