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authorRafael J. Wysocki <rafael.j.wysocki@intel.com>2013-06-19 02:45:34 +0400
committerRafael J. Wysocki <rafael.j.wysocki@intel.com>2013-06-20 02:49:06 +0400
commitb9e95fc65ededbec083aa91b4faa58ad992c0891 (patch)
tree9f2b2867d14e6ad7b6a3cef1a2a776518ae83517 /drivers/acpi/acpi_lpss.c
parent6ee22e9d59151550a55d370b14109bdae8b58bda (diff)
downloadlinux-b9e95fc65ededbec083aa91b4faa58ad992c0891.tar.xz
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.c21
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)