[PATCH] platform/x86: lenovo-wmi-other: Deconflict battery with thinkpad_acpi

[PATCH] platform/x86: lenovo-wmi-other: Deconflict battery with thinkpad_acpi

[Aaron Ma]

ThinkPads expose battery charge thresholds and charge_behaviour through
thinkpad_acpi's ACPI battery hook using raw sysfs attribute groups. The
Lenovo WMI "Other Mode" driver also registers a power_supply_ext for
charge_behaviour and charge_types on systems advertising those WMI
capabilities.

When lenovo-wmi-other registers first, thinkpad_acpi fails to create a
duplicate charge_behaviour sysfs attribute and unregisters its battery
extension. Conversely, registering or updating any power_supply_ext on
the same battery runs sysfs_update_groups(), which removes standard
power-supply attributes not owned by power_supply_core and wipes out
thinkpad_acpi's charge_control_start_threshold,
charge_control_end_threshold, and charge_behaviour files.

Match the existing ideapad_laptop deconfliction and skip registering
the WMI battery extension when CONFIG_THINKPAD_ACPI is enabled and a
ThinkPad ACPI hotkey device (LEN0268, LEN0068, or IBM0068) is present,
unless overridden by force_load_psy_ext.

Fixes: 9ca8fc065b88b ("platform/x86: lenovo-wmi-other: Add WMI battery charge limiting")
Signed-off-by: Aaron Ma <aaron.ma@canonical.com>
---
 drivers/platform/x86/lenovo/wmi-other.c | 14 ++++++++++++--
 1 file changed, 12 insertions(+), 2 deletions(-)

diff --git a/drivers/platform/x86/lenovo/wmi-other.c b/drivers/platform/x86/lenovo/wmi-other.c
index bd64e7b44669d..6175f1e6c51a7 100644
--- a/drivers/platform/x86/lenovo/wmi-other.c
+++ b/drivers/platform/x86/lenovo/wmi-other.c
@@ -909,8 +909,9 @@ static acpi_status lwmi_acpi_match(acpi_handle handle, u32 lvl,
  * lwmi_om_psy_ext_init() - Hooks power supply extension to device battery
  * @priv: Pointer to the lwmi_om_priv drvdata.
  *
- * Checks if the ideapad_laptop driver is going to manage charge attributes first,
- * then if not, hooks the battery to our WMI methods if they are supported.
+ * Checks if the thinkpad_acpi or ideapad_laptop driver is going to manage
+ * charge attributes first, then if not, hooks the battery to our WMI methods
+ * if they are supported.
  */
 static void lwmi_om_psy_ext_init(struct lwmi_om_priv *priv)
 {
@@ -928,6 +929,15 @@ static void lwmi_om_psy_ext_init(struct lwmi_om_priv *priv)
 	if (force_load_psy_ext)
 		goto load_psy_ext;
 
+	/* Deconflict thinkpad_acpi driver */
+	if (IS_ENABLED(CONFIG_THINKPAD_ACPI) &&
+	    (acpi_dev_present("LEN0268", NULL, -1) ||
+	     acpi_dev_present("LEN0068", NULL, -1) ||
+	     acpi_dev_present("IBM0068", NULL, -1))) {
+		dev_dbg(&priv->wdev->dev, "thinkpad_acpi driver manages battery for device\n");
+		return;
+	}
+
 	/* Deconflict ideapad_laptop driver */
 	ret = acpi_get_devices(ideapad_hid, lwmi_acpi_match, &handle, NULL);
 	if (ret)
-- 
2.53.0