The Asus GL502VSK has the same 0B05:1837 keyboard as we've seen in
several Republic of Gamers laptops.
However, in this model, the keybard backlight control exposed by hid-asus
has no effect on the keyboard backlight. Instead, the keyboard
backlight is correctly driven by asus-wmi.
With two keyboard backlight devices available (and only the acer-wmi
one working), GNOME is picking the wrong one to drive in the UI.
Avoid this problem by not creating the backlight interface when we
detect a WMI-driven keyboard backlight.
We have also tested Asus GL702VMK which does have the hid-asus
backlight present, and it still works fine with this patch (WMI method
call returns UNSUPPORTED_METHOD).
Signed-off-by: Daniel Drake <drake@xxxxxxxxxxxx>
---
drivers/hid/Kconfig | 1 +
drivers/hid/hid-asus.c | 53 +++++++++++++++++++++++++++++++++++++++++++++++++-
2 files changed, 53 insertions(+), 1 deletion(-)
diff --git a/drivers/hid/Kconfig b/drivers/hid/Kconfig
index 779c5ae47f36..6d95abc9d8a1 100644
--- a/drivers/hid/Kconfig
+++ b/drivers/hid/Kconfig
@@ -149,6 +149,7 @@ config HID_APPLEIR
config HID_ASUS
tristate "Asus"
depends on LEDS_CLASS
+ depends on ACPI_WMI
---help---
Support for Asus notebook built-in keyboard and touchpad via i2c, and
the Asus Republic of Gamers laptop keyboard special keys.
diff --git a/drivers/hid/hid-asus.c b/drivers/hid/hid-asus.c
index 1bb7b63b3150..e6830946b4a4 100644
--- a/drivers/hid/hid-asus.c
+++ b/drivers/hid/hid-asus.c
@@ -26,6 +26,7 @@
* any later version.
*/
+#include <linux/acpi.h>
#include <linux/hid.h>
#include <linux/module.h>
#include <linux/input/mt.h>
@@ -78,6 +79,12 @@ MODULE_DESCRIPTION("Asus HID Keyboard and TouchPad");
#define TRKID_SGN ((TRKID_MAX + 1) >> 1)
+#define ASUS_WMI_MGMT_GUID "97845ED0-4E6D-11DE-8A39-0800200C9A66"
+#define ASUS_WMI_METHODID_DSTS2 0x53545344 /* Device STatuS #2*/
+#define ASUS_WMI_DEVID_KBD_BACKLIGHT 0x00050021
+#define ASUS_WMI_UNSUPPORTED_METHOD 0xFFFFFFFE
+#define ASUS_WMI_DSTS_PRESENCE_BIT 0x00010000
+
struct asus_kbd_leds {
struct led_classdev cdev;
struct hid_device *hdev;
@@ -330,6 +337,48 @@ static void asus_kbd_backlight_work(struct work_struct *work)
hid_err(led->hdev, "Asus failed to set keyboard backlight: %d\n", ret);
}
+/* WMI-based keyboard backlight LED control (via asus-wmi driver) takes
+ * precedence. We only activate HID-based backlight control when the
+ * WMI control is not available.
+ */
+static bool asus_kbd_wmi_led_control_present(struct hid_device *hdev)
+{
+ u32 args[] = { ASUS_WMI_DEVID_KBD_BACKLIGHT, 0 };
+ struct acpi_buffer input = { (acpi_size) sizeof(args), &args };
+ struct acpi_buffer output = { ACPI_ALLOCATE_BUFFER, NULL };
+ acpi_status status;
+ union acpi_object *obj;
+ u32 value;
+
+ status = wmi_evaluate_method(ASUS_WMI_MGMT_GUID, 0,
+ ASUS_WMI_METHODID_DSTS2,
+ &input, &output);
+
+ if (ACPI_FAILURE(status)) {
+ hid_dbg(hdev, "WMI backlight method failed: %d", status);
+ return false;
+ }
+
+ obj = (union acpi_object *)output.pointer;
+ if (!obj || obj->type != ACPI_TYPE_INTEGER) {
+ hid_dbg(hdev, "WMI backlight method unexpected return type");
+ kfree(obj);
+ return false;
+ }
+
+ value = (u32) obj->integer.value;
+ kfree(obj);
+
+ hid_dbg(hdev, "WMI backlight check: method returned %x", value);
+
+ if (value == ASUS_WMI_UNSUPPORTED_METHOD) {
+ hid_dbg(hdev, "WMI backlight method unsupported");
+ return false;
+ }
+
+ return !!(value & ASUS_WMI_DSTS_PRESENCE_BIT);
+}
+
static int asus_kbd_register_leds(struct hid_device *hdev)
{
struct asus_drvdata *drvdata = hid_get_drvdata(hdev);
@@ -417,7 +466,9 @@ static int asus_input_configured(struct hid_device *hdev, struct hid_input *hi)
drvdata->input = input;
- if (drvdata->enable_backlight && asus_kbd_register_leds(hdev))
+ if (drvdata->enable_backlight &&
+ !asus_kbd_wmi_led_control_present(hdev) &&
+ asus_kbd_register_leds(hdev))
hid_warn(hdev, "Failed to initialize backlight.\n");
return 0;
--
2.14.1
