* [PATCH v2] platform/x86: dell-smbios-wmi: Disable userspace interface if missing hotfix
@ 2017-11-17 4:13 Mario Limonciello
2017-11-17 20:39 ` Darren Hart
0 siblings, 1 reply; 4+ messages in thread
From: Mario Limonciello @ 2017-11-17 4:13 UTC (permalink / raw)
To: dvhart, Andy Shevchenko; +Cc: LKML, platform-driver-x86, Mario Limonciello
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>
---
drivers/platform/x86/dell-smbios-wmi.c | 13 +++++++++++++
drivers/platform/x86/dell-wmi-descriptor.c | 26 ++++++++++++++++++++++++--
drivers/platform/x86/dell-wmi-descriptor.h | 1 +
3 files changed, 38 insertions(+), 2 deletions(-)
diff --git a/drivers/platform/x86/dell-smbios-wmi.c b/drivers/platform/x86/dell-smbios-wmi.c
index 8ad11ef..044a104 100644
--- a/drivers/platform/x86/dell-smbios-wmi.c
+++ b/drivers/platform/x86/dell-smbios-wmi.c
@@ -147,7 +147,10 @@ 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;
+ u32 hotfix;
int count;
int ret;
@@ -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), 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);
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
^ permalink raw reply related [flat|nested] 4+ messages in thread
* Re: [PATCH v2] platform/x86: dell-smbios-wmi: Disable userspace interface if missing hotfix
2017-11-17 4:13 [PATCH v2] platform/x86: dell-smbios-wmi: Disable userspace interface if missing hotfix Mario Limonciello
@ 2017-11-17 20:39 ` Darren Hart
2017-11-20 16:03 ` Mario.Limonciello
0 siblings, 1 reply; 4+ messages in thread
From: Darren Hart @ 2017-11-17 20:39 UTC (permalink / raw)
To: Mario Limonciello; +Cc: Andy Shevchenko, LKML, platform-driver-x86
On Thu, Nov 16, 2017 at 10:13:12PM -0600, Mario Limonciello wrote:
> 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>
Queued up, thanks Mario.
--
Darren Hart
VMware Open Source Technology Center
^ permalink raw reply [flat|nested] 4+ messages in thread
* RE: [PATCH v2] platform/x86: dell-smbios-wmi: Disable userspace interface if missing hotfix
2017-11-17 20:39 ` Darren Hart
@ 2017-11-20 16:03 ` Mario.Limonciello
2017-11-20 20:37 ` Darren Hart
0 siblings, 1 reply; 4+ messages in thread
From: Mario.Limonciello @ 2017-11-20 16:03 UTC (permalink / raw)
To: dvhart; +Cc: andy.shevchenko, linux-kernel, platform-driver-x86
> -----Original Message-----
> From: Darren Hart [mailto:dvhart@infradead.org]
> Sent: Friday, November 17, 2017 2:39 PM
> To: Limonciello, Mario <Mario_Limonciello@Dell.com>
> Cc: Andy Shevchenko <andy.shevchenko@gmail.com>; LKML <linux-
> kernel@vger.kernel.org>; platform-driver-x86@vger.kernel.org
> Subject: Re: [PATCH v2] platform/x86: dell-smbios-wmi: Disable userspace
> interface if missing hotfix
>
> On Thu, Nov 16, 2017 at 10:13:12PM -0600, Mario Limonciello wrote:
> > 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>
>
> Queued up, thanks Mario.
Darren, even though this came after the merge windows opened considering this
restricts the SMBIOS interface from some platform/firmware combinations it
shouldn't be offered, do you think this can be included with a future 4.15
RCx PR so it can land with the rest of the series rather than targeted for 4.16?
I'd hate to get stuck in a situation that an interface deemed "broken" gets offered
to people it shouldn't.
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH v2] platform/x86: dell-smbios-wmi: Disable userspace interface if missing hotfix
2017-11-20 16:03 ` Mario.Limonciello
@ 2017-11-20 20:37 ` Darren Hart
0 siblings, 0 replies; 4+ messages in thread
From: Darren Hart @ 2017-11-20 20:37 UTC (permalink / raw)
To: Mario.Limonciello; +Cc: andy.shevchenko, linux-kernel, platform-driver-x86
On Mon, Nov 20, 2017 at 04:03:53PM +0000, Mario.Limonciello@dell.com wrote:
> > -----Original Message-----
> > From: Darren Hart [mailto:dvhart@infradead.org]
> > Sent: Friday, November 17, 2017 2:39 PM
> > To: Limonciello, Mario <Mario_Limonciello@Dell.com>
> > Cc: Andy Shevchenko <andy.shevchenko@gmail.com>; LKML <linux-
> > kernel@vger.kernel.org>; platform-driver-x86@vger.kernel.org
> > Subject: Re: [PATCH v2] platform/x86: dell-smbios-wmi: Disable userspace
> > interface if missing hotfix
> >
> > On Thu, Nov 16, 2017 at 10:13:12PM -0600, Mario Limonciello wrote:
> > > 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>
> >
> > Queued up, thanks Mario.
>
> Darren, even though this came after the merge windows opened considering this
> restricts the SMBIOS interface from some platform/firmware combinations it
> shouldn't be offered, do you think this can be included with a future 4.15
> RCx PR so it can land with the rest of the series rather than targeted for 4.16?
This will make 4.15.
>
> I'd hate to get stuck in a situation that an interface deemed "broken" gets offered
> to people it shouldn't.
>
Agreed.
--
Darren Hart
VMware Open Source Technology Center
^ permalink raw reply [flat|nested] 4+ messages in thread
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2017-11-17 4:13 [PATCH v2] platform/x86: dell-smbios-wmi: Disable userspace interface if missing hotfix Mario Limonciello
2017-11-17 20:39 ` Darren Hart
2017-11-20 16:03 ` Mario.Limonciello
2017-11-20 20:37 ` Darren Hart
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