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platform/x86: dell-smbios-wmi: Disable userspace interface if missing hotfix

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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@dell.com>
Signed-off-by: Mario Limonciello <mario.limonciello@dell.com>
Signed-off-by: Darren Hart (VMware) <dvhart@infradead.org>
This commit is contained in:
Mario Limonciello 2017-11-16 22:13:12 -06:00 committed by Darren Hart (VMware)
parent aaa40965d2
commit 4255c30fe8
3 changed files with 38 additions and 2 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

13
drivers/platform/x86/dell-smbios-wmi.c
View File

@ -147,7 +147,10 @@ fail_smbios_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;
u32 hotfix;
int count;
int ret;
@ -164,6 +167,16 @@ 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), try upgrading to a newer BIOS\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);

26
drivers/platform/x86/dell-wmi-descriptor.c
View File

@ -27,6 +27,7 @@ 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);
@ -77,6 +78,24 @@ 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:
*
@ -85,6 +104,7 @@ 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)
{
@ -144,15 +164,17 @@ 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);

1
drivers/platform/x86/dell-wmi-descriptor.h
View File

@ -23,5 +23,6 @@ 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