Commit fd70da6a authored by Darren Hart (VMware)'s avatar Darren Hart (VMware)
Browse files

platform/x86: wmi: Require query for data blocks, rename writable to setable 



The Microsoft WMI documentation requires all data blocks to implement
the Query Control Method (WQxx). If we encounter a data block not
implementing this control method, issue a warning, and ignore the data
block. Remove the "readable" attribute as all data blocks must be
readable (query-able).

Be consistent with the language in the documentation, replace the
"writable" attribute with "setable".

Simplify (flatten) the control flow of wmi_create_device a bit while
we are updating it for the above changes.

Signed-off-by: default avatarDarren Hart (VMware) <dvhart@infradead.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Mario Limonciello <mario_limonciello@dell.com>
Cc: Pali Rohár <pali.rohar@gmail.com>
Cc: linux-kernel@vger.kernel.org
Cc: platform-driver-x86@vger.kernel.org
Cc: linux-acpi@vger.kernel.org
Acked-by: default avatarRafael J. Wysocki <rafael.j.wysocki@intel.com>
parent f6301986

drivers/platform/x86/wmi.c

+61 −56
Original line number Diff line number Diff line
@@ -69,7 +69,7 @@ struct wmi_block { 
	wmi_notify_handler handler;

	void *handler_data;



	bool read_takes_no_args;	/* only defined if readable */

	bool read_takes_no_args;

};
@@ -694,28 +694,18 @@ static ssize_t object_id_show(struct device *dev, struct device_attribute *attr, 
}

static DEVICE_ATTR_RO(object_id);



static ssize_t readable_show(struct device *dev, struct device_attribute *attr,

static ssize_t setable_show(struct device *dev, struct device_attribute *attr,

			    char *buf)

{

	struct wmi_device *wdev = dev_to_wdev(dev);



	return sprintf(buf, "%d\n", (int)wdev->readable);

	return sprintf(buf, "%d\n", (int)wdev->setable);

}

static DEVICE_ATTR_RO(readable);



static ssize_t writeable_show(struct device *dev, struct device_attribute *attr,

			      char *buf)

{

	struct wmi_device *wdev = dev_to_wdev(dev);



	return sprintf(buf, "%d\n", (int)wdev->writeable);

}

static DEVICE_ATTR_RO(writeable);

static DEVICE_ATTR_RO(setable);



static struct attribute *wmi_data_attrs[] = {

	&dev_attr_object_id.attr,

	&dev_attr_readable.attr,

	&dev_attr_writeable.attr,

	&dev_attr_setable.attr,

	NULL,

};

ATTRIBUTE_GROUPS(wmi_data);
@@ -833,33 +823,42 @@ static struct device_type wmi_type_data = { 
	.release = wmi_dev_release,

};



static void wmi_create_device(struct device *wmi_bus_dev,

static int wmi_create_device(struct device *wmi_bus_dev,

			     const struct guid_block *gblock,

			     struct wmi_block *wblock,

			     struct acpi_device *device)

{

	wblock->dev.dev.bus = &wmi_bus_type;

	wblock->dev.dev.parent = wmi_bus_dev;



	dev_set_name(&wblock->dev.dev, "%pUL", gblock->guid);



	if (gblock->flags & ACPI_WMI_EVENT) {

		wblock->dev.dev.type = &wmi_type_event;

	} else if (gblock->flags & ACPI_WMI_METHOD) {

		wblock->dev.dev.type = &wmi_type_method;

	} else {

	struct acpi_device_info *info;

	char method[5];

	int result;



		wblock->dev.dev.type = &wmi_type_data;

	if (gblock->flags & ACPI_WMI_EVENT) {

		wblock->dev.dev.type = &wmi_type_event;

		goto out_init;

	}



	if (gblock->flags & ACPI_WMI_METHOD) {

		wblock->dev.dev.type = &wmi_type_method;

		goto out_init;

	}



	/*

	 * Data Block Query Control Method (WQxx by convention) is

	 * required per the WMI documentation. If it is not present,

	 * we ignore this data block.

	 */

	strcpy(method, "WQ");

	strncat(method, wblock->gblock.object_id, 2);

	result = get_subobj_info(device->handle, method, &info);



		if (result == 0) {

			wblock->dev.readable = true;

	if (result) {

		dev_warn(wmi_bus_dev,

			 "%s data block query control method not found",

			 method);

		return result;

	}



	wblock->dev.dev.type = &wmi_type_data;



	/*

	 * The Microsoft documentation specifically states:
@@ -867,29 +866,31 @@ static void wmi_create_device(struct device *wmi_bus_dev, 
	 *   Data blocks registered with only a single instance

	 *   can ignore the parameter.

	 *

			 * ACPICA will get mad at us if we call the method

			 * with the wrong number of arguments, so check what

			 * our method expects.  (On some Dell laptops, WQxx

			 * may not be a method at all.)

	 * ACPICA will get mad at us if we call the method with the wrong number

	 * of arguments, so check what our method expects.  (On some Dell

	 * laptops, WQxx may not be a method at all.)

	 */

			if (info->type != ACPI_TYPE_METHOD ||

			    info->param_count == 0)

	if (info->type != ACPI_TYPE_METHOD || info->param_count == 0)

		wblock->read_takes_no_args = true;



	kfree(info);

		}



	strcpy(method, "WS");

	strncat(method, wblock->gblock.object_id, 2);

	result = get_subobj_info(device->handle, method, NULL);



		if (result == 0) {

			wblock->dev.writeable = true;

		}

	if (result == 0)

		wblock->dev.setable = true;



	}

 out_init:

	wblock->dev.dev.bus = &wmi_bus_type;

	wblock->dev.dev.parent = wmi_bus_dev;



	dev_set_name(&wblock->dev.dev, "%pUL", gblock->guid);



	device_initialize(&wblock->dev.dev);



	return 0;

}



static void wmi_free_devices(struct acpi_device *device)
@@ -978,7 +979,11 @@ static int parse_wdg(struct device *wmi_bus_dev, struct acpi_device *device) 
		wblock->acpi_device = device;

		wblock->gblock = gblock[i];



		wmi_create_device(wmi_bus_dev, &gblock[i], wblock, device);

		retval = wmi_create_device(wmi_bus_dev, &gblock[i], wblock, device);

		if (retval) {

			kfree(wblock);

			continue;

		}



		list_add_tail(&wblock->list, &wmi_block_list);

include/linux/wmi.h

+2 −5
Original line number Diff line number Diff line
@@ -22,11 +22,8 @@ 
struct wmi_device {

	struct device dev;



	/*

	 * These are true for data objects that support reads and writes,

	 * respectively.

	 */

	bool readable, writeable;

	 /* True for data blocks implementing the Set Control Method */

	bool setable;

};



/* Caller must kfree the result. */

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