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author | Rafael J. Wysocki <rjw@sisk.pl> | 2012-05-20 13:58:00 +0200 |
---|---|---|
committer | Rafael J. Wysocki <rjw@sisk.pl> | 2012-05-29 21:20:24 +0200 |
commit | 38c92fff988d518fe80dc23d0d44d66bd7e47ddd (patch) | |
tree | c18cc469f47bf0e79f3617c59175978e60f31878 /drivers | |
parent | ACPI / PM: Fix error messages in drivers/acpi/bus.c (diff) | |
download | linux-38c92fff988d518fe80dc23d0d44d66bd7e47ddd.tar.xz linux-38c92fff988d518fe80dc23d0d44d66bd7e47ddd.zip |
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>
Diffstat (limited to 'drivers')
-rw-r--r-- | drivers/acpi/bus.c | 51 | ||||
-rw-r--r-- | drivers/acpi/power.c | 2 |
2 files changed, 30 insertions, 23 deletions
diff --git a/drivers/acpi/bus.c b/drivers/acpi/bus.c index a41be56c1cc0..adceafda9c17 100644 --- a/drivers/acpi/bus.c +++ b/drivers/acpi/bus.c @@ -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))); diff --git a/drivers/acpi/power.c b/drivers/acpi/power.c index 0500f719f63e..dd6d6a3c6780 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_HOT; i++) { + for (i = ACPI_STATE_D0; i <= ACPI_STATE_D3_HOT; i++) { list = &device->power.states[i].resources; if (list->count < 1) continue; |