We are testing different M.2 SSD on AGX and found a 4 lane SSD worked on AGX.
Our question is how to setup ‘num-lanes’ of ‘pcie@14180000’?
From the link below, used a 4 lane M.2 SSD on Agx, the ‘num-lanes’ of ‘pcie@14180000’ is supposed to set to 4.
The thing is the ‘num-lanes’ of ‘pcie@14180000’ is 8 in R31.1 by default, and a 4 lane SSD works.
It’s confused and we don’t know how to set it correctly.
Well, Ideally you don’t need to update ‘num-lanes’ as an x8 controller can work with an x4 and x2 cards without any issues.
Having said that, we did encounter Realtek NVMe controller-based NVMe cards which advertise x2 capability and they seem to have issues with Jetson-Xavier boards and the solution for that is to update ‘num-lanes’ to ‘2’.
Bottom line is, edit ‘num-lanes’ only if something doesn’t work.
Due to some M.2 SSD do not work on Agx Javier with agx released SDK.
Is there any criteria and/or compatibility listing for the devices which work on Xavier?
Well, as I mentioned, all M.2 SSDs have been working till we found the issue with SSD based on Realtek NVMe controller which is a x2 capable controller (from the config space) but looks wise it appears to be a x4 card.
So, this is the only card/controller for which an edit in ‘num-lanes’ property is required. Otherwise, all M.2 SSDs should work without any issue.