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>
dell-wmi and dell-smbios-wmi are dependent upon dell-wmi-descriptor
finishing probe successfully to probe themselves.
Currently if dell-wmi-descriptor fails probing in a non-recoverable way
(such as invalid header) dell-wmi and dell-smbios-wmi will continue to
try to redo probing due to deferred probing.
To solve this have the dependent drivers query the dell-wmi-descriptor
driver whether the descriptor has been determined valid. The possible
results are:
-ENODEV: Descriptor GUID missing from WMI bus
-EPROBE_DEFER: Descriptor not yet probed, dependent driver should wait
and use deferred probing
< 0: Descriptor probed, invalid. Dependent driver should return an
error.
0: Successful descriptor probe, dependent driver can continue
Successful descriptor probe still doesn't mean that the descriptor driver
is necessarily bound at the time of initialization of dependent driver.
Userspace can unbind the driver, so all methods used from driver
should still be verified to return success values otherwise deferred
probing be used.
Signed-off-by: Mario Limonciello <mario.limonciello@dell.com>
Reviewed-by: Pali Rohár <pali.rohar@gmail.com>
Signed-off-by: Darren Hart (VMware) <dvhart@infradead.org>
devm_kzalloc will return NULL pointer if no memory was allocated.
This should be checked. This problem also existed when the driver
was dell-wmi.c.
Signed-off-by: Mario Limonciello <mario.limonciello@dell.com>
Reviewed-by: Pali Rohár <pali.rohar@gmail.com>
Signed-off-by: Darren Hart (VMware) <dvhart@infradead.org>
All communication on individual GUIDs should occur in separate drivers.
Allowing a driver to communicate with the bus to another GUID is just
a hack that discourages drivers to adopt the bus model.
The information found from the WMI descriptor driver is now exported
for use by other drivers.
Signed-off-by: Mario Limonciello <mario.limonciello@dell.com>
Reviewed-by: Edward O'Callaghan <quasisec@google.com>
Signed-off-by: Darren Hart (VMware) <dvhart@infradead.org>
