Commit e0668f28 authored by Yurii Pavlovskyi's avatar Yurii Pavlovskyi Committed by Andy Shevchenko
Browse files

platform/x86: asus-wmi: Improve DSTS WMI method ID detection 

The DSTS method detection mistakenly selects DCTS instead of DSTS if
nothing is returned when the method ID is not defined in WMNB. As a result,
the control of keyboard backlight is not functional for TUF Gaming series
laptops. Implement detection based on _UID of the WMI device instead.

There is evidence that DCTS is handled by ACPI WMI devices that have _UID
ASUSWMI, whereas none of the devices without ASUSWMI respond to DCTS and
DSTS is used instead [1].

DSDT examples:

FX505GM (_UID ATK):
Method (WMNB, 3, Serialized)
{ ...
    If ((Local0 == 0x53545344))
    {
        ...
        Return (Zero)
    }
    ...
    // No return
}

K54C (_UID ATK):
Method (WMNB, 3, Serialized)
{ ...
    If ((Local0 == 0x53545344))
    {
        ...
        Return (0x02)
    }
    ...
    Return (0xFFFFFFFE)
}

[1] Link: https://lkml.org/lkml/2019/4/11/322



Signed-off-by: default avatarYurii Pavlovskyi <yurii.pavlovskyi@gmail.com>
Suggested-by: default avatarDaniel Drake <drake@endlessm.com>
Signed-off-by: default avatarAndy Shevchenko <andriy.shevchenko@linux.intel.com>
parent e7488e58

drivers/hid/hid-asus.c

+1 −1
Original line number Diff line number Diff line
@@ -396,7 +396,7 @@ static bool asus_kbd_wmi_led_control_present(struct hid_device *hdev) 
	if (!IS_ENABLED(CONFIG_ASUS_WMI))

		return false;



	ret = asus_wmi_evaluate_method(ASUS_WMI_METHODID_DSTS2,

	ret = asus_wmi_evaluate_method(ASUS_WMI_METHODID_DSTS,

				       ASUS_WMI_DEVID_KBD_BACKLIGHT, 0, &value);

	hid_dbg(hdev, "WMI backlight check: rc %d value %x", ret, value);

	if (ret)

drivers/platform/x86/asus-wmi.c

+20 −3
Original line number Diff line number Diff line
@@ -83,6 +83,8 @@ MODULE_LICENSE("GPL"); 
#define USB_INTEL_XUSB2PR		0xD0

#define PCI_DEVICE_ID_INTEL_LYNXPOINT_LP_XHCI	0x9c31



#define ASUS_ACPI_UID_ASUSWMI		"ASUSWMI"



static const char * const ashs_ids[] = { "ATK4001", "ATK4002", NULL };



static bool ashs_present(void)
@@ -1874,6 +1876,8 @@ static int asus_wmi_sysfs_init(struct platform_device *device) 
 */

static int asus_wmi_platform_init(struct asus_wmi *asus)

{

	struct device *dev = &asus->platform_device->dev;

	char *wmi_uid;

	int rv;



	/* INIT enable hotkeys on some models */
@@ -1903,11 +1907,24 @@ static int asus_wmi_platform_init(struct asus_wmi *asus) 
	 * Note, on most Eeepc, there is no way to check if a method exist

	 * or note, while on notebooks, they returns 0xFFFFFFFE on failure,

	 * but once again, SPEC may probably be used for that kind of things.

	 *

	 * Additionally at least TUF Gaming series laptops return nothing for

	 * unknown methods, so the detection in this way is not possible.

	 *

	 * There is strong indication that only ACPI WMI devices that have _UID

	 * equal to "ASUSWMI" use DCTS whereas those with "ATK" use DSTS.

	 */

	if (!asus_wmi_evaluate_method(ASUS_WMI_METHODID_DSTS, 0, 0, NULL))

	wmi_uid = wmi_get_acpi_device_uid(ASUS_WMI_MGMT_GUID);

	if (!wmi_uid)

		return -ENODEV;



	if (!strcmp(wmi_uid, ASUS_ACPI_UID_ASUSWMI)) {

		dev_info(dev, "Detected ASUSWMI, use DCTS\n");

		asus->dsts_id = ASUS_WMI_METHODID_DCTS;

	} else {

		dev_info(dev, "Detected %s, not ASUSWMI, use DSTS\n", wmi_uid);

		asus->dsts_id = ASUS_WMI_METHODID_DSTS;

	else

		asus->dsts_id = ASUS_WMI_METHODID_DSTS2;

	}



	/* CWAP allow to define the behavior of the Fn+F2 key,

	 * this method doesn't seems to be present on Eee PCs */

include/linux/platform_data/x86/asus-wmi.h

+2 −2
Original line number Diff line number Diff line
@@ -18,8 +18,8 @@ 
#define ASUS_WMI_METHODID_GDSP		0x50534447 /* Get DiSPlay output */

#define ASUS_WMI_METHODID_DEVP		0x50564544 /* DEVice Policy */

#define ASUS_WMI_METHODID_OSVR		0x5256534F /* OS VeRsion */

#define ASUS_WMI_METHODID_DSTS		0x53544344 /* Device STatuS */

#define ASUS_WMI_METHODID_DSTS2		0x53545344 /* Device STatuS #2*/

#define ASUS_WMI_METHODID_DCTS		0x53544344 /* Device status (DCTS) */

#define ASUS_WMI_METHODID_DSTS		0x53545344 /* Device status (DSTS) */

#define ASUS_WMI_METHODID_BSTS		0x53545342 /* Bios STatuS ? */

#define ASUS_WMI_METHODID_DEVS		0x53564544 /* DEVice Set */

#define ASUS_WMI_METHODID_CFVS		0x53564643 /* CPU Frequency Volt Set */

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