Version 4.2 cannot detect PCIe M.2 slot

Robotics & Edge Computing Jetson & Embedded Systems Jetson AGX Xavier
1

Hi,

I just bought a Ampack wifi module and plugged into the M.2 slot, and my Jetson Agx Xavier was not able to detect it. and I notice that you have this issue related to PCIe where the 3.3v is not there, does the PCIe slot and the M.2 share the same powergate ?
# cat /sys/kernel/debug/powergate
powergate powered
------------------
aud no
disp yes
dispb no
dispc no
ispa no
nvdeca no
nvjpg no
nvenca no
nvencb no
nvdecb no
sax no
ve no
vic no
xusba yes
xusbb no
xusbc yes
pciex8a no
pciex4a no
pciex1a yes
nvl no
pciex8b no
pvaa no
pvab no
dlaa no
dlab no
cv no
gpu no

3

Please describe the problem in detail like which M.2 slot? key E or key M? Compare to which PCIe slot? They all share same 3.3v rail.

4

This PCIe slot:

image
image852×736 75.2 KB

and this M2 key slot:
image
image2000×1333 804 KB

how do I check in the system side is the 3.3v has been enabled ?

5

They share same VDD_3V3 of carrier board, it should be always ON when system on. You can probe it on any components on the rail by checking the schematic of P2822 in DLC.

6

Hi Do I need to enable the M2.Key slot in the kernel ? or it is turned on by default ?

8

Is this issue on the M.2 key slot or the pcie slot?

Are you able to see any new device in “lspci”?