From: João Paulo Rechi Vita jprvita@gmail.com
[ Upstream commit 78f3ac76d9e5219589718b9e4733bee21627b3f5 ]
In the past, Asus firmwares would change the panel backlight directly through the EC when the display off hotkey (Fn+F7) was pressed, and only notify the OS of such change, with 0x33 when the LCD was ON and 0x34 when the LCD was OFF. These are currently mapped to KEY_DISPLAYTOGGLE and KEY_DISPLAY_OFF, respectively.
Most recently the EC on Asus most machines lost ability to toggle the LCD backlight directly, but unless the OS informs the firmware it is going to handle the display toggle hotkey events, the firmware still tries change the brightness through the EC, to no effect. The end result is a long list (at Endless we counted 11) of Asus laptop models where the display toggle hotkey does not perform any action. Our firmware engineers contacts at Asus were surprised that there were still machines out there with the old behavior.
Calling WMNB(ASUS_WMI_DEVID_BACKLIGHT==0x00050011, 2) on the _WDG device tells the firmware that it should let the OS handle the display toggle event, in which case it will simply notify the OS of a key press with 0x35, as shown by the DSDT excerpts bellow.
Scope (_SB) { (...)
Device (ATKD) { (...)
Name (_WDG, Buffer (0x28) { /* 0000 */ 0xD0, 0x5E, 0x84, 0x97, 0x6D, 0x4E, 0xDE, 0x11, /* 0008 */ 0x8A, 0x39, 0x08, 0x00, 0x20, 0x0C, 0x9A, 0x66, /* 0010 */ 0x4E, 0x42, 0x01, 0x02, 0x35, 0xBB, 0x3C, 0x0B, /* 0018 */ 0xC2, 0xE3, 0xED, 0x45, 0x91, 0xC2, 0x4C, 0x5A, /* 0020 */ 0x6D, 0x19, 0x5D, 0x1C, 0xFF, 0x00, 0x01, 0x08 }) Method (WMNB, 3, Serialized) { CreateDWordField (Arg2, Zero, IIA0) CreateDWordField (Arg2, 0x04, IIA1) Local0 = (Arg1 & 0xFFFFFFFF)
(...)
If ((Local0 == 0x53564544)) { (...)
If ((IIA0 == 0x00050011)) { If ((IIA1 == 0x02)) { ^^PCI0.SBRG.EC0.SPIN (0x72, One) ^^PCI0.SBRG.EC0.BLCT = One }
Return (One) } } (...) } (...) } (...) } (...)
Scope (_SB.PCI0.SBRG.EC0) { (...)
Name (BLCT, Zero)
(...)
Method (_Q10, 0, NotSerialized) // _Qxx: EC Query { If ((BLCT == Zero)) { Local0 = One Local0 = RPIN (0x72) Local0 ^= One SPIN (0x72, Local0) If (ATKP) { Local0 = (0x34 - Local0) ^^^^ATKD.IANE (Local0) } } ElseIf ((BLCT == One)) { If (ATKP) { ^^^^ATKD.IANE (0x35) } } } (...) }
Signed-off-by: João Paulo Rechi Vita jprvita@endlessm.com Signed-off-by: Andy Shevchenko andriy.shevchenko@linux.intel.com Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/platform/x86/asus-wmi.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/drivers/platform/x86/asus-wmi.c b/drivers/platform/x86/asus-wmi.c index c285a16675ee..37b5de541270 100644 --- a/drivers/platform/x86/asus-wmi.c +++ b/drivers/platform/x86/asus-wmi.c @@ -2131,7 +2131,8 @@ static int asus_wmi_add(struct platform_device *pdev) err = asus_wmi_backlight_init(asus); if (err && err != -ENODEV) goto fail_backlight; - } + } else + err = asus_wmi_set_devstate(ASUS_WMI_DEVID_BACKLIGHT, 2, NULL);
status = wmi_install_notify_handler(asus->driver->event_guid, asus_wmi_notify, asus);