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path: root/drivers/platform/x86/dell/dell-wmi-ddv.c
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2023-07-11platform/x86: dell-ddv: Improve error handlingArmin Wolf
If for some reason a external function returns -ENODEV, no error message is being displayed because the driver assumes that -ENODEV can only be returned internally if no sensors, etc where found. Fix this by explicitly returning 0 in such a case since missing hardware is no error. Also remove the now obsolete check for -ENODEV. Signed-off-by: Armin Wolf <W_Armin@gmx.de> Link: https://lore.kernel.org/r/20230707010333.12954-1-W_Armin@gmx.de Reviewed-by: Hans de Goede <hdegoede@redhat.com> Signed-off-by: Hans de Goede <hdegoede@redhat.com>
2023-03-07platform/x86: dell-ddv: Fix temperature scalingArmin Wolf
After using the built-in UEFI hardware diagnostics to compare the measured battery temperature, i noticed that the temperature is actually expressed in tenth degree kelvin, similar to the SBS-Data standard. For example, a value of 2992 is displayed as 26 degrees celsius. Fix the scaling so that the correct values are being displayed. Tested on a Dell Inspiron 3505. Fixes: a77272c16041 ("platform/x86: dell: Add new dell-wmi-ddv driver") Signed-off-by: Armin Wolf <W_Armin@gmx.de> Link: https://lore.kernel.org/r/20230218115318.20662-2-W_Armin@gmx.de Signed-off-by: Hans de Goede <hdegoede@redhat.com> Reviewed-by: Hans de Goede <hdegoede@redhat.com>
2023-03-07platform/x86: dell-ddv: Fix cache invalidation on resumeArmin Wolf
If one or both sensor buffers could not be initialized, either due to missing hardware support or due to some error during probing, the resume handler will encounter undefined behaviour when attempting to lock buffers then protected by an uninitialized or destroyed mutex. Fix this by introducing a "active" flag which is set during probe, and only invalidate buffers which where flaged as "active". Tested on a Dell Inspiron 3505. Fixes: 3b7eeff93d29 ("platform/x86: dell-ddv: Add hwmon support") Signed-off-by: Armin Wolf <W_Armin@gmx.de> Link: https://lore.kernel.org/r/20230218115318.20662-1-W_Armin@gmx.de Signed-off-by: Hans de Goede <hdegoede@redhat.com> Reviewed-by: Hans de Goede <hdegoede@redhat.com>
2023-02-13platform/x86: dell-ddv: Prefer asynchronous probingArmin Wolf
During probe, both sensor buffers need to be queried to initialize the hwmon channels. This might be slow on some machines, causing a unnecessary delay during boot. Mark the driver with PROBE_PREFER_ASYNCHRONOUS so that it can be probed asynchronously. Signed-off-by: Armin Wolf <W_Armin@gmx.de> Link: https://lore.kernel.org/r/20230209211503.2739-3-W_Armin@gmx.de Reviewed-by: Hans de Goede <hdegoede@redhat.com> Signed-off-by: Hans de Goede <hdegoede@redhat.com>
2023-02-13platform/x86: dell-ddv: Add hwmon supportArmin Wolf
Thanks to bugreport 216655 on bugzilla triggered by the dell-smm-hwmon driver, the contents of the sensor buffers could be almost completely decoded. Add an hwmon interface for exposing the fan and thermal sensor values. Since the WMI interface can be quite slow on some machines, the sensor buffers are cached for 1 second to lessen the performance impact. The debugfs interface remains in place to aid in reverse-engineering of unknown sensor types and the thermal buffer. Tested-by: AntonĂ­n Skala <skala.antonin@gmail.com> Tested-by: Gustavo Walbon <gustavowalbon@gmail.com> Signed-off-by: Armin Wolf <W_Armin@gmx.de> Reviewed-by: Guenter Roeck <linux@roeck-us.net> Link: https://lore.kernel.org/r/20230209211503.2739-2-W_Armin@gmx.de Reviewed-by: Hans de Goede <hdegoede@redhat.com> Signed-off-by: Hans de Goede <hdegoede@redhat.com>
2023-02-03platform/x86: dell-ddv: Add "force" module paramArmin Wolf
Until now, the dell-wmi-ddv driver needs to be manually patched and compiled to test compatibility with unknown DDV WMI interface versions. Add a module param to allow users to force loading even when a unknown interface version was detected. Since this might cause various unwanted side effects, the module param is marked as unsafe. Signed-off-by: Armin Wolf <W_Armin@gmx.de> Link: https://lore.kernel.org/r/20230126194021.381092-5-W_Armin@gmx.de Reviewed-by: Hans de Goede <hdegoede@redhat.com> Signed-off-by: Hans de Goede <hdegoede@redhat.com>
2023-02-03platform/x86: dell-ddv: Replace EIO with ENOMSGArmin Wolf
When the ACPI WMI interface returns a valid ACPI object which has the wrong type, then ENOMSG instead of EIO should be returned, since the WMI method was still successfully evaluated. Signed-off-by: Armin Wolf <W_Armin@gmx.de> Link: https://lore.kernel.org/r/20230126194021.381092-4-W_Armin@gmx.de Reviewed-by: Hans de Goede <hdegoede@redhat.com> Signed-off-by: Hans de Goede <hdegoede@redhat.com>
2023-02-03platform/x86: dell-ddv: Return error if buffer is emptyArmin Wolf
In several cases, the DDV WMI interface can return buffers with a length of zero. Return -ENODATA in such a case for proper error handling. Also replace some -EIO errors with more specialized ones. Signed-off-by: Armin Wolf <W_Armin@gmx.de> Link: https://lore.kernel.org/r/20230126194021.381092-3-W_Armin@gmx.de Reviewed-by: Hans de Goede <hdegoede@redhat.com> Signed-off-by: Hans de Goede <hdegoede@redhat.com>
2023-02-03platform/x86: dell-ddv: Add support for interface version 3Armin Wolf
While trying to solve a bugreport on bugzilla, i learned that some devices (for example the Dell XPS 17 9710) provide a more recent DDV WMI interface (version 3). Since the new interface version just adds an additional method, no code changes are necessary apart from whitelisting the version. Signed-off-by: Armin Wolf <W_Armin@gmx.de> Link: https://lore.kernel.org/r/20230126194021.381092-2-W_Armin@gmx.de Reviewed-by: Hans de Goede <hdegoede@redhat.com> Signed-off-by: Hans de Goede <hdegoede@redhat.com>
2022-11-16platform/x86: dell-ddv: Warn if ePPID has a suspicious lengthArmin Wolf
On some systems (like the Dell Inspiron 3505), the acpi operation region holding the ePPID string is two bytes too short, causing acpi functions like ToString() to omit the last two bytes. This does not happen on Windows, supposedly due to their implementation of ToString() ignoring buffer boundaries. Inform users if the ePPID length differs from the Dell specification so they can complain to Dell to fix their BIOS. Tested on a Dell Inspiron 3505. Signed-off-by: Armin Wolf <W_Armin@gmx.de> Link: https://lore.kernel.org/r/20221102212336.380257-2-W_Armin@gmx.de Reviewed-by: Hans de Goede <hdegoede@redhat.com> Signed-off-by: Hans de Goede <hdegoede@redhat.com>
2022-11-16platform/x86: dell-ddv: Improve buffer handlingArmin Wolf
When the DDV interface returns a buffer, it actually returns a acpi buffer containing an integer (buffer size) and another acpi buffer (buffer content). The size of the buffer may be smaller than the size of the buffer content, which is perfectly valid and should not be treated as an error. Also use the buffer size instead of the buffer content size when accessing the buffer to prevent accessing bogus data. Tested on a Dell Inspiron 3505. Signed-off-by: Armin Wolf <W_Armin@gmx.de> Link: https://lore.kernel.org/r/20221102212336.380257-1-W_Armin@gmx.de Reviewed-by: Hans de Goede <hdegoede@redhat.com> Signed-off-by: Hans de Goede <hdegoede@redhat.com>
2022-11-16platform/x86: dell: Add new dell-wmi-ddv driverArmin Wolf
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>