Currently, WMI drivers have to use the deprecated GUID-based
interface when setting data blocks. This prevents those
drivers from fully moving away from this interface.
Provide wmidev_block_set() so drivers using wmi_set_block() can
fully migrate to the modern bus-based interface.
Tested with a custom SSDT from the Intel Slim Bootloader project.
Signed-off-by: Armin Wolf <W_Armin@gmx.de>
Link: https://lore.kernel.org/r/20231103182526.3524-1-W_Armin@gmx.de
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Since commit fa1f68db6c ("drivers: misc: pass miscdevice pointer via
file private data"), the miscdevice stores a pointer to itself inside
filp->private_data, which means that private_data will not be NULL when
wmi_char_open() is called. This might cause memory corruption should
wmi_char_open() be unable to find its driver, something which can
happen when the associated WMI device is deleted in wmi_free_devices().
Fix the problem by using the miscdevice pointer to retrieve the WMI
device data associated with a char device using container_of(). This
also avoids wmi_char_open() picking a wrong WMI device bound to a
driver with the same name as the original driver.
Fixes: 44b6b76611 ("platform/x86: wmi: create userspace interface for drivers")
Signed-off-by: Armin Wolf <W_Armin@gmx.de>
Link: https://lore.kernel.org/r/20231020211005.38216-5-W_Armin@gmx.de
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
When a WMI device besides the first one somehow fails to register,
retval is returned while still containing a negative error code. This
causes the ACPI device fail to probe, leaving behind zombie WMI devices
leading to various errors later.
Handle the single error path separately and return 0 unconditionally
after trying to register all WMI devices to solve the issue. Also
continue to register WMI devices even if some fail to allocate memory.
Fixes: 6ee50aaa9a ("platform/x86: wmi: Instantiate all devices before adding them")
Signed-off-by: Armin Wolf <W_Armin@gmx.de>
Link: https://lore.kernel.org/r/20231020211005.38216-4-W_Armin@gmx.de
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Until now, legacy GUID-based functions where using find_guid() when
searching for WMI devices, which did no refcounting on the returned
WMI device. This meant that the WMI device could disappear at any
moment, potentially leading to various errors. Fix this by using
bus_find_device() which returns an actual reference to the found
WMI device.
Signed-off-by: Armin Wolf <W_Armin@gmx.de>
Link: https://lore.kernel.org/r/20231020211005.38216-3-W_Armin@gmx.de
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Many aggregate WMI drivers do not use -EPROBE_DEFER when they
cannot find a WMI device during probe, instead they require
all WMI devices associated with an platform device to become
available at once. This is currently achieved by adding those
WMI devices to the wmi_block_list before they are registered,
which is then used by the deprecated GUID-based functions to
search for WMI devices.
Replace this approach with a device link which defers probing
of the WMI device until the associated platform device has finished
probing (and has registered all WMI devices). New aggregate WMI
drivers should not rely on this behaviour.
Signed-off-by: Armin Wolf <W_Armin@gmx.de>
Link: https://lore.kernel.org/r/20231020211005.38216-2-W_Armin@gmx.de
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
The while-loop may break on one of the two conditions, either ID string
is empty or GUID matches. The second one, may never be reached if the
parsed string is not correct GUID. In such a case the loop will never
advance to check the next ID.
Break possible infinite loop by factoring out guid_parse_and_compare()
helper which may be moved to the generic header for everyone later on
and preventing from similar mistake in the future.
Interestingly that firstly it appeared when WMI was turned into a bus
driver, but later when duplicated GUIDs were checked, the while-loop
has been replaced by for-loop and hence no mistake made again.
Fixes: a48e23385f ("platform/x86: wmi: add context pointer field to struct wmi_device_id")
Fixes: 844af950da ("platform/x86: wmi: Turn WMI into a bus driver")
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20230621151155.78279-1-andriy.shevchenko@linux.intel.com
Tested-by: Armin Wolf <W_Armin@gmx.de>
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Currently, the WMI driver core knows how many instances of a given
WMI object exist, but WMI drivers cannot access this information.
At the same time, some current and upcoming WMI drivers want to
have access to this information. Add wmi_instance_count() and
wmidev_instance_count() to allow WMI drivers to get the number of
WMI object instances.
Signed-off-by: Armin Wolf <W_Armin@gmx.de>
Link: https://lore.kernel.org/r/20230430203153.5587-2-W_Armin@gmx.de
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
The WMI driver core supports a more mordern bus-based interface for
interacting with WMI devices. The older GUID-based interface depends
on each WMI GUID and notification id being unique on a given system,
which turned out is not the case.
Mark the older interface as deprecated since new WMI drivers should
use the bus-based interface to avoid this issues.
Signed-off-by: Armin Wolf <W_Armin@gmx.de>
Tested-by: Randy Dunlap <rdunlap@infradead.org>
Acked-by: Randy Dunlap <rdunlap@infradead.org>
Link: https://lore.kernel.org/r/20230424222939.208137-3-W_Armin@gmx.de
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
The .remove() callback for a platform driver returns an int which makes
many driver authors wrongly assume it's possible to do error handling by
returning an error code. However the value returned is (mostly) ignored
and this typically results in resource leaks. To improve here there is a
quest to make the remove callback return void. In the first step of this
quest all drivers are converted to .remove_new() which already returns
void.
Trivially convert this driver from always returning zero in the remove
callback to the void returning variant.
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Link: https://lore.kernel.org/r/20230302144732.1903781-29-u.kleine-koenig@pengutronix.de
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
The dell-wmi-ddv driver adds support for reading
the current temperature and ePPID of ACPI batteries
on supported Dell machines.
Since the WMI interface used by this driver does not
do any input validation and thus cannot be used for probing,
the driver depends on the ACPI battery extension machanism
to discover batteries.
The driver also supports a debugfs interface for retrieving
buffers containing fan and thermal sensor information.
Since the meaing of the content of those buffers is currently
unknown, the interface is meant for reverse-engineering and
will likely be replaced with an hwmon interface once the
meaning has been understood.
The driver was tested on a Dell Inspiron 3505.
Signed-off-by: Armin Wolf <W_Armin@gmx.de>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20220927204521.601887-3-W_Armin@gmx.de
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
The WMI subsystem in the kernel currently tracks WMI devices by
a GUID string not by ACPI device. The GUID used by the `wmi-bmof`
module however is available from many devices on nearly every machine.
This originally was thought to be a bug, but as it happens on most
machines it is a design mistake. It has been fixed by tying an ACPI
device to the driver with struct wmi_driver. So drivers that have
moved over to struct wmi_driver can actually support multiple
instantiations of a GUID without any problem.
Add an allow list into wmi.c for GUIDs that the drivers that are known
to use struct wmi_driver. The list is populated with `wmi-bmof` right
now. The additional instances of that in sysfs with be suffixed with -%d
Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
Link: https://lore.kernel.org/r/20220829201500.6341-1-mario.limonciello@amd.com
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
The driver core sets struct device->driver before calling out
to the bus' probe() method, this leaves a window where an ACPI
notify may happen on the WMI object before the driver's
probe() method has completed running, causing e.g. the
driver's notify() callback to get called with drvdata
not yet being set leading to a NULL pointer deref.
At a check for this to the WMI core, ensuring that the notify()
callback is not called before the driver is ready.
Fixes: 1686f54445 ("platform/x86: wmi: Incorporate acpi_install_notify_handler")
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Link: https://lore.kernel.org/r/20211128190031.405620-2-hdegoede@redhat.com
Previously, `__query_block()` would fail if the
second WCxx method call failed. However, the
WQxx method might have succeeded, and potentially
allocated memory for the result. Instead of
throwing away the result and potentially
leaking memory, ignore the result of
the second WCxx call.
Signed-off-by: Barnabás Pőcze <pobrn@protonmail.com>
Link: https://lore.kernel.org/r/20210904175450.156801-25-pobrn@protonmail.com
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
