ASPM Tuning script
This script lets you enable ASPM on your devices in case your BIOS does not have it enabled for some reason. If your BIOS does not have it enabled it is usually for a good reason so you should only use this if you know what you are doing. Typically you would only need to enable ASPM manually when doing development and using a card that typically is not present on a laptop, or using the cardbus slot. The BIOS typically disables ASPM for foreign cards and on the cardbus slot. Check also if you may need to do other things than what is below on your vendor documentation.
To use this script You will need for now to at least query your device PCI endpoint and root complex addresses using the convention output by lspci: []:[].[]
For example:
03:00.0 Network controller: Atheros Communications Inc. AR9300 Wireless LAN adaptor (rev 01 00:1c.1 PCI bridge: Intel Corporation 82801H (ICH8 Family) PCI Express Port 2 (rev 03)
The root complex for the endpoint can be found using lspci -t
For more details refer to:
http://wireless.kernel.org/en/users/Documentation/ASPM
You just need to modify these three values:
#ROOT_COMPLEX="00:1c.1"
#ROOT_COMPLEX="00:1e.0"
ROOT_COMPLEX="00:1c.3"
#ENDPOINT="03:00.0"
#ENDPOINT="05:00.0"
ENDPOINT="05:00.0"
We'll only enable the last 2 bits by using a mask of :3 to setpci, this will ensure we keep the existing values on the byte.
| Hex | Binary | Meaning |
|---|---|---|
| 0 | 0b00 | L0 only |
| 1 | 0b01 | L0s only |
| 2 | 0b10 | L1 only |
| 3 | 0b11 | L1 and L0s |