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Date: Thu, 16 Nov 2017 14:48:30 -0600
From: Mario Limonciello <mario.limonciello@...l.com>
To: dvhart@...radead.org, Andy Shevchenko <andy.shevchenko@...il.com>
Cc: LKML <linux-kernel@...r.kernel.org>,
platform-driver-x86@...r.kernel.org,
Mario Limonciello <mario.limonciello@...l.com>
Subject: [PATCH] platform/x86: dell-smbios-wmi: Disable userspace interface if missing hotfix
The Dell SMBIOS WMI interface will fail for some more complex calls unless
a WMI hotfix has been included. Most platforms have this fix available in
a maintenance BIOS release. In the case the driver is loaded on a
platform without this fix, disable the userspace interface.
A hotfix indicator is present in the dell-wmi-descriptor that represents
whether or not more complex calls will work properly.
"Simple" calls such as those used by dell-laptop and dell-wmi will continue
to work properly so dell-smbios-wmi should not be blocked from binding and
being used as the dell-smbios dispatcher.
Suggested-by: Girish Prakash <girish.prakash@...l.com>
Signed-off-by: Mario Limonciello <mario.limonciello@...l.com>
---
drivers/platform/x86/dell-smbios-wmi.c | 14 ++++++++++++++
drivers/platform/x86/dell-wmi-descriptor.c | 26 ++++++++++++++++++++++++--
drivers/platform/x86/dell-wmi-descriptor.h | 1 +
3 files changed, 39 insertions(+), 2 deletions(-)
diff --git a/drivers/platform/x86/dell-smbios-wmi.c b/drivers/platform/x86/dell-smbios-wmi.c
index 8ad11ef..a296551 100644
--- a/drivers/platform/x86/dell-smbios-wmi.c
+++ b/drivers/platform/x86/dell-smbios-wmi.c
@@ -147,9 +147,12 @@ static long dell_smbios_wmi_filter(struct wmi_device *wdev, unsigned int cmd,
static int dell_smbios_wmi_probe(struct wmi_device *wdev)
{
+ struct wmi_driver *wdriver =
+ container_of(wdev->dev.driver, struct wmi_driver, driver);
struct wmi_smbios_priv *priv;
int count;
int ret;
+ u32 hotfix;
if (!wmi_has_guid(DELL_WMI_DESCRIPTOR_GUID))
return -ENODEV;
@@ -167,6 +170,16 @@ static int dell_smbios_wmi_probe(struct wmi_device *wdev)
if (!dell_wmi_get_size(&priv->req_buf_size))
return -EPROBE_DEFER;
+ /* some SMBIOS calls fail unless BIOS contains hotfix */
+ if (!dell_wmi_get_hotfix(&hotfix))
+ return -EPROBE_DEFER;
+ if (!hotfix) {
+ dev_warn(&wdev->dev,
+ "WMI SMBIOS userspace interface not supported (%u)\n",
+ hotfix);
+ wdriver->filter_callback = NULL;
+ }
+
/* add in the length object we will use internally with ioctl */
priv->req_buf_size += sizeof(u64);
ret = set_required_buffer_size(wdev, priv->req_buf_size);
@@ -184,6 +197,7 @@ static int dell_smbios_wmi_probe(struct wmi_device *wdev)
if (ret)
goto fail_register;
+
priv->wdev = wdev;
dev_set_drvdata(&wdev->dev, priv);
mutex_lock(&list_mutex);
diff --git a/drivers/platform/x86/dell-wmi-descriptor.c b/drivers/platform/x86/dell-wmi-descriptor.c
index e7f4c3a..5083ce0 100644
--- a/drivers/platform/x86/dell-wmi-descriptor.c
+++ b/drivers/platform/x86/dell-wmi-descriptor.c
@@ -25,6 +25,7 @@ struct descriptor_priv {
struct list_head list;
u32 interface_version;
u32 size;
+ u32 hotfix;
};
static int descriptor_valid = -EPROBE_DEFER;
static LIST_HEAD(wmi_list);
@@ -72,6 +73,24 @@ bool dell_wmi_get_size(u32 *size)
}
EXPORT_SYMBOL_GPL(dell_wmi_get_size);
+bool dell_wmi_get_hotfix(u32 *hotfix)
+{
+ struct descriptor_priv *priv;
+ bool ret = false;
+
+ mutex_lock(&list_mutex);
+ priv = list_first_entry_or_null(&wmi_list,
+ struct descriptor_priv,
+ list);
+ if (priv) {
+ *hotfix = priv->hotfix;
+ ret = true;
+ }
+ mutex_unlock(&list_mutex);
+ return ret;
+}
+EXPORT_SYMBOL_GPL(dell_wmi_get_hotfix);
+
/*
* Descriptor buffer is 128 byte long and contains:
*
@@ -80,6 +99,7 @@ EXPORT_SYMBOL_GPL(dell_wmi_get_size);
* Object Signature 4 4 " WMI"
* WMI Interface Version 8 4 <version>
* WMI buffer length 12 4 <length>
+ * WMI hotfix number 16 4 <hotfix>
*/
static int dell_wmi_descriptor_probe(struct wmi_device *wdev)
{
@@ -139,15 +159,17 @@ static int dell_wmi_descriptor_probe(struct wmi_device *wdev)
priv->interface_version = buffer[2];
priv->size = buffer[3];
+ priv->hotfix = buffer[4];
ret = 0;
dev_set_drvdata(&wdev->dev, priv);
mutex_lock(&list_mutex);
list_add_tail(&priv->list, &wmi_list);
mutex_unlock(&list_mutex);
- dev_dbg(&wdev->dev, "Detected Dell WMI interface version %lu and buffer size %lu\n",
+ dev_dbg(&wdev->dev, "Detected Dell WMI interface version %lu, buffer size %lu, hotfix %lu\n",
(unsigned long) priv->interface_version,
- (unsigned long) priv->size);
+ (unsigned long) priv->size,
+ (unsigned long) priv->hotfix);
out:
kfree(obj);
diff --git a/drivers/platform/x86/dell-wmi-descriptor.h b/drivers/platform/x86/dell-wmi-descriptor.h
index 776cddd..217b833 100644
--- a/drivers/platform/x86/dell-wmi-descriptor.h
+++ b/drivers/platform/x86/dell-wmi-descriptor.h
@@ -24,5 +24,6 @@ int dell_wmi_get_descriptor_valid(void);
bool dell_wmi_get_interface_version(u32 *version);
bool dell_wmi_get_size(u32 *size);
+bool dell_wmi_get_hotfix(u32 *hotfix);
#endif
--
2.7.4
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