From: "Darren Hart (VMware)" <dvh...@infradead.org>
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: Darren Hart (VMware) <dvh...@infradead.org>
Cc: Andy Lutomirski <l...@amacapital.net>
Cc: Mario Limonciello <mario_limoncie...@dell.com>
Cc: Pali Rohár <pali.ro...@gmail.com>
Cc: Rafael Wysocki <r...@rjwysocki.net>
Cc: linux-kernel@vger.kernel.org
Cc: platform-driver-...@vger.kernel.org
Cc: linux-a...@vger.kernel.org
---
drivers/platform/x86/wmi.c | 117 +++++++++++++++++++++++----------------------
include/linux/wmi.h | 7 +--
2 files changed, 63 insertions(+), 61 deletions(-)
diff --git a/drivers/platform/x86/wmi.c b/drivers/platform/x86/wmi.c
index 8dd9988..cc55952 100644
--- a/drivers/platform/x86/wmi.c
+++ b/drivers/platform/x86/wmi.c
@@ -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,
- char *buf)
+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);
@@ -833,63 +823,74 @@ 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);
+ struct acpi_device_info *info;
+ char method[5];
+ int result;
if (gblock->flags & ACPI_WMI_EVENT) {
wblock->dev.dev.type = &wmi_type_event;
- } else if (gblock->flags & ACPI_WMI_METHOD) {
+ goto out_init;
+ }
+
+ if (gblock->flags & ACPI_WMI_METHOD) {
wblock->dev.dev.type = &wmi_type_method;
- } else {
- struct acpi_device_info *info;
- char method[5];
- int result;
+ goto out_init;
+ }
- wblock->dev.dev.type = &wmi_type_data;
+ /*
+ * 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) {
+ dev_warn(wmi_bus_dev,
+ "%s data block query control method not found",
+ method);
+ return result;
+ }
- strcpy(method, "WQ");
- strncat(method, wblock->gblock.object_id, 2);
- result = get_subobj_info(device->handle, method, &info);
+ wblock->dev.dev.type = &wmi_type_data;
- if (result == 0) {
- wblock->dev.readable = true;
+ /*
+ * The Microsoft documentation specifically states:
+ *
+ * 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.)
+ */
+ if (info->type != ACPI_TYPE_METHOD || info->param_count == 0)
+ wblock->read_takes_no_args = true;
- /*
- * The Microsoft documentation specifically states:
- *
- * 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.)
- */
- if (info->type != ACPI_TYPE_METHOD ||
- info->param_count == 0)
- wblock->read_takes_no_args = true;
+ kfree(info);
- kfree(info);
- }
+ strcpy(method, "WS");
+ strncat(method, wblock->gblock.object_id, 2);
+ result = get_subobj_info(device->handle, method, NULL);
- strcpy(method, "WS");
- strncat(method, wblock->gblock.object_id, 2);
- result = get_subobj_info(device->handle, method, NULL);
+ if (result == 0)
+ wblock->dev.setable = true;
- if (result == 0) {
- wblock->dev.writeable = 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)
@@ -985,7 +986,11 @@ 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);
diff --git a/include/linux/wmi.h b/include/linux/wmi.h
index a283768..cd0d773 100644
--- a/include/linux/wmi.h
+++ b/include/linux/wmi.h
@@ -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. */
--
2.9.4
