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authorRafael J. Wysocki <rafael.j.wysocki@intel.com>2017-08-01 03:56:18 +0300
committerRafael J. Wysocki <rafael.j.wysocki@intel.com>2017-08-01 15:05:03 +0300
commit1ba51a7c1496fd8f6d5bdd58dafcb1894275b7f0 (patch)
tree84c8f2f2035e2973765e2b9103e475a9bad1607b /drivers/acpi/device_pm.c
parent99d8845e756cb91e2865f430401d084cd6a8ccc9 (diff)
downloadlinux-1ba51a7c1496fd8f6d5bdd58dafcb1894275b7f0.tar.xz
ACPI / PCI / PM: Rework acpi_pci_propagate_wakeup()
The acpi_pci_propagate_wakeup() routine is there to handle cases in which PCI bridges (or PCIe ports) are expected to signal wakeup for devices below them, but currently it doesn't do that correctly. The problem is that acpi_pci_propagate_wakeup() uses acpi_pm_set_device_wakeup() for bridges and if that routine is called for multiple times to disable wakeup for the same device, it will disable it on the first invocation and the next calls will have no effect (it works analogously when called to enable wakeup, but that is not a problem). Now, say acpi_pci_propagate_wakeup() has been called for two different devices under the same bridge and it has called acpi_pm_set_device_wakeup() for that bridge each time. The bridge is now enabled to generate wakeup signals. Next, suppose that one of the devices below it resumes and acpi_pci_propagate_wakeup() is called to disable wakeup for that device. It will then call acpi_pm_set_device_wakeup() for the bridge and that will effectively disable remote wakeup for all devices under it even though some of them may still be suspended and remote wakeup may be expected to work for them. To address this (arguably theoretical) issue, allow wakeup.enable_count under struct acpi_device to grow beyond 1 in certain situations. In particular, allow that to happen in acpi_pci_propagate_wakeup() when wakeup is enabled or disabled for PCI bridges, so that wakeup is actually disabled for the bridge when all devices under it resume and not when just one of them does that. Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com> Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com> Acked-by: Bjorn Helgaas <bhelgaas@google.com>
Diffstat (limited to 'drivers/acpi/device_pm.c')
-rw-r--r--drivers/acpi/device_pm.c72
1 files changed, 50 insertions, 22 deletions
diff --git a/drivers/acpi/device_pm.c b/drivers/acpi/device_pm.c
index 4cd4bdab053d..112fd6c55c2c 100644
--- a/drivers/acpi/device_pm.c
+++ b/drivers/acpi/device_pm.c
@@ -684,19 +684,8 @@ static void acpi_pm_notify_work_func(struct acpi_device_wakeup_context *context)
static DEFINE_MUTEX(acpi_wakeup_lock);
-/**
- * acpi_device_wakeup_enable - Enable wakeup functionality for device.
- * @adev: ACPI device to enable wakeup functionality for.
- * @target_state: State the system is transitioning into.
- *
- * Enable the GPE associated with @adev so that it can generate wakeup signals
- * for the device in response to external (remote) events and enable wakeup
- * power for it.
- *
- * Callers must ensure that @adev is a valid ACPI device node before executing
- * this function.
- */
-static int acpi_device_wakeup_enable(struct acpi_device *adev, u32 target_state)
+static int __acpi_device_wakeup_enable(struct acpi_device *adev,
+ u32 target_state, int max_count)
{
struct acpi_device_wakeup *wakeup = &adev->wakeup;
acpi_status status;
@@ -704,9 +693,12 @@ static int acpi_device_wakeup_enable(struct acpi_device *adev, u32 target_state)
mutex_lock(&acpi_wakeup_lock);
- if (wakeup->enable_count > 0)
+ if (wakeup->enable_count >= max_count)
goto out;
+ if (wakeup->enable_count > 0)
+ goto inc;
+
error = acpi_enable_wakeup_device_power(adev, target_state);
if (error)
goto out;
@@ -718,6 +710,7 @@ static int acpi_device_wakeup_enable(struct acpi_device *adev, u32 target_state)
goto out;
}
+inc:
wakeup->enable_count++;
out:
@@ -726,6 +719,23 @@ out:
}
/**
+ * acpi_device_wakeup_enable - Enable wakeup functionality for device.
+ * @adev: ACPI device to enable wakeup functionality for.
+ * @target_state: State the system is transitioning into.
+ *
+ * Enable the GPE associated with @adev so that it can generate wakeup signals
+ * for the device in response to external (remote) events and enable wakeup
+ * power for it.
+ *
+ * Callers must ensure that @adev is a valid ACPI device node before executing
+ * this function.
+ */
+static int acpi_device_wakeup_enable(struct acpi_device *adev, u32 target_state)
+{
+ return __acpi_device_wakeup_enable(adev, target_state, 1);
+}
+
+/**
* acpi_device_wakeup_disable - Disable wakeup functionality for device.
* @adev: ACPI device to disable wakeup functionality for.
*
@@ -752,12 +762,8 @@ out:
mutex_unlock(&acpi_wakeup_lock);
}
-/**
- * acpi_pm_set_device_wakeup - Enable/disable remote wakeup for given device.
- * @dev: Device to enable/disable to generate wakeup events.
- * @enable: Whether to enable or disable the wakeup functionality.
- */
-int acpi_pm_set_device_wakeup(struct device *dev, bool enable)
+static int __acpi_pm_set_device_wakeup(struct device *dev, bool enable,
+ int max_count)
{
struct acpi_device *adev;
int error;
@@ -777,13 +783,35 @@ int acpi_pm_set_device_wakeup(struct device *dev, bool enable)
return 0;
}
- error = acpi_device_wakeup_enable(adev, acpi_target_system_state());
+ error = __acpi_device_wakeup_enable(adev, acpi_target_system_state(),
+ max_count);
if (!error)
dev_dbg(dev, "Wakeup enabled by ACPI\n");
return error;
}
-EXPORT_SYMBOL(acpi_pm_set_device_wakeup);
+
+/**
+ * acpi_pm_set_device_wakeup - Enable/disable remote wakeup for given device.
+ * @dev: Device to enable/disable to generate wakeup events.
+ * @enable: Whether to enable or disable the wakeup functionality.
+ */
+int acpi_pm_set_device_wakeup(struct device *dev, bool enable)
+{
+ return __acpi_pm_set_device_wakeup(dev, enable, 1);
+}
+EXPORT_SYMBOL_GPL(acpi_pm_set_device_wakeup);
+
+/**
+ * acpi_pm_set_bridge_wakeup - Enable/disable remote wakeup for given bridge.
+ * @dev: Bridge device to enable/disable to generate wakeup events.
+ * @enable: Whether to enable or disable the wakeup functionality.
+ */
+int acpi_pm_set_bridge_wakeup(struct device *dev, bool enable)
+{
+ return __acpi_pm_set_device_wakeup(dev, enable, INT_MAX);
+}
+EXPORT_SYMBOL_GPL(acpi_pm_set_bridge_wakeup);
/**
* acpi_dev_pm_low_power - Put ACPI device into a low-power state.