From fd70da6a6267c91fbdda9c560f098cfd52fba00f Mon Sep 17 00:00:00 2001 From: "Darren Hart (VMware)" Date: Fri, 19 May 2017 19:28:36 -0700 Subject: [PATCH] platform/x86: wmi: Require query for data blocks, rename writable to setable MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit 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) Cc: Andy Lutomirski Cc: Mario Limonciello Cc: Pali Rohár Cc: linux-kernel@vger.kernel.org Cc: platform-driver-x86@vger.kernel.org Cc: linux-acpi@vger.kernel.org Acked-by: Rafael J. Wysocki --- 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 250d7b2..37f6651 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) @@ -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); 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. */ -- 2.7.4