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| 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 /drivers/acpi/acpi_lpss.c | |
| parent | 6ee22e9d59151550a55d370b14109bdae8b58bda (diff) | |
| download | lwn-b9e95fc65ededbec083aa91b4faa58ad992c0891.tar.gz lwn-b9e95fc65ededbec083aa91b4faa58ad992c0891.zip | |
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>
Diffstat (limited to 'drivers/acpi/acpi_lpss.c')
| -rw-r--r-- | drivers/acpi/acpi_lpss.c | 21 |
1 files changed, 15 insertions, 6 deletions
diff --git a/drivers/acpi/acpi_lpss.c b/drivers/acpi/acpi_lpss.c index 652fd5ce303c..cab13f2fc28e 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) |