RE: [PATCH v2] platform/x86: dell-smbios-wmi: Disable userspace interface if missing hotfix

From: Mario.Limonciello
Date: Mon Nov 20 2017 - 11:04:04 EST

> -----Original Message-----
> From: Darren Hart [mailto:dvhart@xxxxxxxxxxxxx]
> Sent: Friday, November 17, 2017 2:39 PM
> To: Limonciello, Mario <Mario_Limonciello@xxxxxxxx>
> Cc: Andy Shevchenko <andy.shevchenko@xxxxxxxxx>; LKML <linux-
> kernel@xxxxxxxxxxxxxxx>; platform-driver-x86@xxxxxxxxxxxxxxx
> 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@xxxxxxxx>
> > Signed-off-by: Mario Limonciello <mario.limonciello@xxxxxxxx>
> 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.