I am trying to enable S3 wakeup from USB keyboard in Linux.
After boot, if i execute in terminal command <cat /proc/acpi/wakeup> i get:
Device S-state Status Sysfs node
PCI0 S5 disabled no-bus:pci0000:00
HDEF S4 disabled pci:0000:00:1b.0
RP01 S5 disabled pci:0000:00:1c.0
RP02 S5 disabled pci:0000:00:1c.1
RP03 S5 disabled pci:0000:00:1c.2
RP04 S5 disabled pci:0000:00:1c.3
RP05 S5 disabled pci:0000:00:1c.4
RP06 S5 disabled pci:0000:00:1c.5
USB1 S3 disabled pci:0000:00:1d.0
USB2 S3 disabled pci:0000:00:1d.1
USB3 S3 disabled pci:0000:00:1d.2
USB4 S3 disabled pci:0000:00:1d.3
EHC1 S3 disabled pci:0000:00:1d.7
MODM S4 disabled
COMA S3 disabled pnp:00:08
COMB S3 disabled pnp:00:09
At my guess, current devices are devices from DSDT table with _PRW method. But for some reason (why?) wakeup for them disabled by default.
I can enable wakeup for keyboard (in my case it is USB1) with:
echo PCI0 > /proc/acpi/wakeup
echo USB1 > /proc/acpi/wakeup
Throught some experiments i figured out, that these commands says to OS, that it should enable appropriate bits in ACPI GPE0_EN register before going to S3 (what bits exactly is defined in PCI0._PRW and USB1._PRW)
But this is not the end. I think OS power off USB controller when it goes to S3. To fix this i found device USB number from dmesg:
[ 2.724374] input: LITEON Technology USB Multimedia Keyboard as /devices/pci0000:00/0000:00:1d.0/usb2/2-2/2-2:1.0/input/input6
And executed command <echo enabled > /sys/bus/usb/devices/2-2/power/wakeup>
And only now wakeup from USB fully works.
My question is, how i should change DSDT/BIOS, to avoid all of these commands?
I think main problem is a lack of something in DSDT.
Some fragments from current DSDT:
...
Device (USB1)
{
Name(_ADR, 0x001D0000)
Name(_PRW, Package(0x02){ 0x03, 0x03 })
Method(_S3D,0)
{
Return(2)
}
}
...
Scope (\_GPE)
{
..
// USB1
Method (_L03, 0)
{
Notify (\_SB.PCI0.USB1, 0x02)
}
..
}