Fw: [linux-pm] [patch 2.6.21-rc5-git 2/3] ACPI driver model flags and platform_enable_wake()

Jordan Crouse jordan.crouse at amd.com
Sun Apr 8 12:54:57 EDT 2007


Forward to devel@

----- Forwarded message from David Brownell <david-b at pacbell.net> -----

From: David Brownell <david-b at pacbell.net>
Date: Thu, 5 Apr 2007 12:49:10 -0700
To: linux-acpi at vger.kernel.org, linux-pm at lists.linux-foundation.org
Subject: [linux-pm] [patch 2.6.21-rc5-git 2/3] ACPI driver model flags
 and platform_enable_wake()

This upgrades the ACPI code to start cooperating with the two driver
model wakeup flags and with pci_enable_wake(), based on the previous
patch updating that PCI call:

 - The physical device's "device.power.can_wakeup" flag tracks the ACPI
   flag "acpi_device.wakeup.flags.valid" ... the latter can't entirely
   vanish, since it's initialized before the "real device" node exists.

 - Implements the new platform_enable_wakeup() hook.  This does the same
   thing as manual writes to /proc/acpi/wakeup:  it sets a flag that is
   tested later, to remember whether the GPE should be enabled before
   entering a system sleep state.

 - The GPEs are not set if the physical device's "should_wakeup" flag
   has been cleared.  That's purely a policy input, through sysfs, at the
   level of "that hardware is flakey, ignore its wake events".

ACPI systems see behavioral changes as follows:

   * Wakeup-aware PCI drivers no longer need to have someone override the
     initial system config by writing to /proc/acpi/wakeup; existing calls
     to pci_enable_wake() suffice.  For wakeup-unaware drivers, it's still
     not clearly safe to enable wakeup in /proc/acpi/wakeup.

   * Non-PCI frameworks (as for PS2 serial ports) could call the platform
     hook like PCI does, supporting wakeup-aware drivers.

   * The /sys/devices/.../power/wakeup flags are a different kind of manual
     override.  They _disable_ wakeup for broken hardware or drivers, rather
     than _enabling_ it in the hope that unmodified drivers won't break when
     their hardware triggers wakeup events.

Arguably, it's now time to modify /proc/acpi/wakeup to ignore writes; and
have it display the relevant GPE not an internal flag.

Note a key omission:  only motherboard devices are listed in the ACPI
tables, so add-on devices aren't covered.  The USB framework handles
those devices; but nothing in this patch handles PCI add-in cards.

Another open issue is the ACPI framework's current inability to manage
wakeup events for systems in the S0 state.  That kind of runtime PM is
allowed by PCI and by common hardware (e.g. ICH6).

Includes a semi-related bugfix:  the input devices for the ACPI buttons
weren't set up to link to the "physical" ACPI device node.

Signed-off-by: David Brownell <dbrownell at users.sourceforge.net>
---
 drivers/acpi/button.c       |    5 +++++
 drivers/acpi/glue.c         |    9 ++++++++-
 drivers/acpi/power.c        |    4 ++++
 drivers/acpi/sleep/wakeup.c |   40 ++++++++++++++++++++++++++++++++++++++++
 4 files changed, 57 insertions(+), 1 deletion(-)

--- g26.orig/drivers/acpi/glue.c	2007-04-04 13:57:02.000000000 -0700
+++ g26/drivers/acpi/glue.c	2007-04-04 13:57:03.000000000 -0700
@@ -146,6 +146,7 @@ EXPORT_SYMBOL(acpi_get_physical_device);
 
 static int acpi_bind_one(struct device *dev, acpi_handle handle)
 {
+	struct acpi_device *device;
 	acpi_status status;
 
 	if (dev->archdata.acpi_handle) {
@@ -161,6 +162,11 @@ static int acpi_bind_one(struct device *
 	}
 	dev->archdata.acpi_handle = handle;
 
+	/* init driver model state */
+	status = acpi_bus_get_device(handle, &device);
+	if (!ACPI_FAILURE(status))
+		device_init_wakeup(dev, device->wakeup.flags.valid);
+
 	return 0;
 }
 
@@ -196,7 +202,8 @@ static int acpi_platform_notify(struct d
 	}
 	type = acpi_get_bus_type(dev->bus);
 	if (!type) {
-		DBG("No ACPI bus support for %s\n", dev->bus_id);
+		DBG("No ACPI bus support for %s:%s\n",
+				dev->bus->name, dev->bus_id);
 		ret = -EINVAL;
 		goto end;
 	}
--- g26.orig/drivers/acpi/button.c	2007-04-04 13:53:56.000000000 -0700
+++ g26/drivers/acpi/button.c	2007-04-05 11:54:59.000000000 -0700
@@ -366,6 +366,7 @@ static int acpi_button_add(struct acpi_d
 		error = -ENOMEM;
 		goto err_free_button;
 	}
+	input->cdev.dev = &device->dev;
 
 	/*
 	 * Determine the button type (via hid), as fixed-feature buttons
@@ -444,6 +445,10 @@ static int acpi_button_add(struct acpi_d
 	if (error)
 		goto err_remove_handlers;
 
+	/* for these devices the ACPI node *IS* the "physical" device */
+	device_init_wakeup(&device->dev, device->wakeup.flags.valid);
+	/* REVISIT prefer acpi_bind_one(&device->dev, device->handle); */
+
 	if (device->wakeup.flags.valid) {
 		/* Button's GPE is run-wake GPE */
 		acpi_set_gpe_type(device->wakeup.gpe_device,
--- g26.orig/drivers/acpi/power.c	2007-04-04 13:53:56.000000000 -0700
+++ g26/drivers/acpi/power.c	2007-04-04 13:57:03.000000000 -0700
@@ -322,6 +322,7 @@ int acpi_enable_wakeup_device_power(stru
 		ret = acpi_power_on(dev->wakeup.resources.handles[i], dev);
 		if (ret) {
 			printk(KERN_ERR PREFIX "Transition power state\n");
+			device_init_wakeup(&dev->dev, 0);
 			dev->wakeup.flags.valid = 0;
 			return -1;
 		}
@@ -331,6 +332,7 @@ int acpi_enable_wakeup_device_power(stru
 	status = acpi_evaluate_object(dev->handle, "_PSW", &arg_list, NULL);
 	if (ACPI_FAILURE(status) && (status != AE_NOT_FOUND)) {
 		printk(KERN_ERR PREFIX "Evaluate _PSW\n");
+		device_init_wakeup(&dev->dev, 0);
 		dev->wakeup.flags.valid = 0;
 		ret = -1;
 	}
@@ -360,6 +362,7 @@ int acpi_disable_wakeup_device_power(str
 	status = acpi_evaluate_object(dev->handle, "_PSW", &arg_list, NULL);
 	if (ACPI_FAILURE(status) && (status != AE_NOT_FOUND)) {
 		printk(KERN_ERR PREFIX "Evaluate _PSW\n");
+		device_init_wakeup(&dev->dev, 0);
 		dev->wakeup.flags.valid = 0;
 		return -1;
 	}
@@ -369,6 +372,7 @@ int acpi_disable_wakeup_device_power(str
 		ret = acpi_power_off_device(dev->wakeup.resources.handles[i], dev);
 		if (ret) {
 			printk(KERN_ERR PREFIX "Transition power state\n");
+			device_init_wakeup(&dev->dev, 0);
 			dev->wakeup.flags.valid = 0;
 			return -1;
 		}
--- g26.orig/drivers/acpi/sleep/wakeup.c	2007-04-04 13:53:56.000000000 -0700
+++ g26/drivers/acpi/sleep/wakeup.c	2007-04-04 13:57:03.000000000 -0700
@@ -36,12 +36,22 @@ void acpi_enable_wakeup_device_prep(u8 s
 		struct acpi_device *dev = container_of(node,
 						       struct acpi_device,
 						       wakeup_list);
+		struct device *ldev;
 
 		if (!dev->wakeup.flags.valid ||
 		    !dev->wakeup.state.enabled ||
 		    (sleep_state > (u32) dev->wakeup.sleep_state))
 			continue;
 
+		ldev = acpi_get_physical_device(dev->handle);
+		if (ldev) {
+			int flag = device_may_wakeup(ldev);
+
+			put_device(ldev);
+			if (!flag)
+				continue;
+		}
+
 		spin_unlock(&acpi_device_lock);
 		acpi_enable_wakeup_device_power(dev);
 		spin_lock(&acpi_device_lock);
@@ -68,6 +78,7 @@ void acpi_enable_wakeup_device(u8 sleep_
 		struct acpi_device *dev = container_of(node,
 						       struct acpi_device,
 						       wakeup_list);
+		struct device *ldev;
 
 		/* If users want to disable run-wake GPE,
 		 * we only disable it for wake and leave it for runtime
@@ -89,6 +100,15 @@ void acpi_enable_wakeup_device(u8 sleep_
 		    (sleep_state > (u32) dev->wakeup.sleep_state))
 			continue;
 
+		ldev = acpi_get_physical_device(dev->handle);
+		if (ldev) {
+			int flag = device_may_wakeup(ldev);
+
+			put_device(ldev);
+			if (!flag)
+				continue;
+		}
+
 		spin_unlock(&acpi_device_lock);
 		/* run-wake GPE has been enabled */
 		if (!dev->wakeup.flags.run_wake)
@@ -149,6 +169,24 @@ void acpi_disable_wakeup_device(u8 sleep
 	spin_unlock(&acpi_device_lock);
 }
 
+static int acpi_platform_enable_wakeup(struct device *dev, int is_on)
+{
+	struct acpi_device	*adev;
+	int			status;
+
+	if (!device_can_wakeup(dev))
+		return -EINVAL;
+	if (is_on && !device_may_wakeup(dev))
+		return -EINVAL;
+
+	status = acpi_bus_get_device(DEVICE_ACPI_HANDLE(dev), &adev);
+	if (status < 0)
+		return status;
+
+	adev->wakeup.state.enabled = !!is_on;
+	return 0;
+}
+
 static int __init acpi_wakeup_device_init(void)
 {
 	struct list_head *node, *next;
@@ -156,6 +194,8 @@ static int __init acpi_wakeup_device_ini
 	if (acpi_disabled)
 		return 0;
 
+	platform_enable_wakeup = acpi_platform_enable_wakeup;
+
 	spin_lock(&acpi_device_lock);
 	list_for_each_safe(node, next, &acpi_wakeup_device_list) {
 		struct acpi_device *dev = container_of(node,
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----- End forwarded message -----

-- 
Jordan Crouse
Senior Linux Engineer
Advanced Micro Devices, Inc.
<www.amd.com/embeddedprocessors>




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