diff options
| author | Rafael J. Wysocki <rafael.j.wysocki@intel.com> | 2013-06-19 00:45:34 +0200 |
|---|---|---|
| committer | Rafael J. Wysocki <rafael.j.wysocki@intel.com> | 2013-06-20 00:49:06 +0200 |
| commit | b9e95fc65ededbec083aa91b4faa58ad992c0891 (patch) | |
| tree | 9f2b2867d14e6ad7b6a3cef1a2a776518ae83517 | |
| parent | 6ee22e9d59151550a55d370b14109bdae8b58bda (diff) | |
ACPI / LPSS: Power up LPSS devices during enumeration
Commit 7cd8407 (ACPI / PM: Do not execute _PS0 for devices without
_PSC during initialization) introduced a regression on some systems
with Intel Lynxpoint Low-Power Subsystem (LPSS) where some devices
need to be powered up during initialization, but their device objects
in the ACPI namespace have _PS0 and _PS3 only (without _PSC or power
resources).
To work around this problem, make the ACPI LPSS driver power up
devices it knows about by using a new helper function
acpi_device_fix_up_power() that does all of the necessary
sanity checks and calls acpi_dev_pm_explicit_set() to put the
device into D0.
Reported-and-tested-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
| -rw-r--r-- | drivers/acpi/acpi_lpss.c | 21 | ||||
| -rw-r--r-- | drivers/acpi/device_pm.c | 20 | ||||
| -rw-r--r-- | include/acpi/acpi_bus.h | 1 |
3 files changed, 36 insertions, 6 deletions
diff --git a/drivers/acpi/acpi_lpss.c b/drivers/acpi/acpi_lpss.c index 652fd5ce303..cab13f2fc28 100644 --- a/drivers/acpi/acpi_lpss.c +++ b/drivers/acpi/acpi_lpss.c @@ -164,15 +164,24 @@ static int acpi_lpss_create_device(struct acpi_device *adev, if (dev_desc->clk_required) { ret = register_device_clock(adev, pdata); if (ret) { - /* - * Skip the device, but don't terminate the namespace - * scan. - */ - kfree(pdata); - return 0; + /* Skip the device, but continue the namespace scan. */ + ret = 0; + goto err_out; } } + /* + * This works around a known issue in ACPI tables where LPSS devices + * have _PS0 and _PS3 without _PSC (and no power resources), so + * acpi_bus_init_power() will assume that the BIOS has put them into D0. + */ + ret = acpi_device_fix_up_power(adev); + if (ret) { + /* Skip the device, but continue the namespace scan. */ + ret = 0; + goto err_out; + } + adev->driver_data = pdata; ret = acpi_create_platform_device(adev, id); if (ret > 0) diff --git a/drivers/acpi/device_pm.c b/drivers/acpi/device_pm.c index 318fa32a141..31c217a4283 100644 --- a/drivers/acpi/device_pm.c +++ b/drivers/acpi/device_pm.c @@ -290,6 +290,26 @@ int acpi_bus_init_power(struct acpi_device *device) return 0; } +/** + * acpi_device_fix_up_power - Force device with missing _PSC into D0. + * @device: Device object whose power state is to be fixed up. + * + * Devices without power resources and _PSC, but having _PS0 and _PS3 defined, + * are assumed to be put into D0 by the BIOS. However, in some cases that may + * not be the case and this function should be used then. + */ +int acpi_device_fix_up_power(struct acpi_device *device) +{ + int ret = 0; + + if (!device->power.flags.power_resources + && !device->power.flags.explicit_get + && device->power.state == ACPI_STATE_D0) + ret = acpi_dev_pm_explicit_set(device, ACPI_STATE_D0); + + return ret; +} + int acpi_bus_update_power(acpi_handle handle, int *state_p) { struct acpi_device *device; diff --git a/include/acpi/acpi_bus.h b/include/acpi/acpi_bus.h index 636c59f2003..c13c919ab99 100644 --- a/include/acpi/acpi_bus.h +++ b/include/acpi/acpi_bus.h @@ -382,6 +382,7 @@ const char *acpi_power_state_string(int state); int acpi_device_get_power(struct acpi_device *device, int *state); int acpi_device_set_power(struct acpi_device *device, int state); int acpi_bus_init_power(struct acpi_device *device); +int acpi_device_fix_up_power(struct acpi_device *device); int acpi_bus_update_power(acpi_handle handle, int *state_p); bool acpi_bus_power_manageable(acpi_handle handle); |