PolarFire-SoC
PCIe Root Port support in Linux-- connecting a device to the Icicle Kit #40
Replies: 3 comments 9 replies
-
|
Just plugged in a standard Samsung NVMe via an adapter; it works fine:
So it looks like the issue I am experiencing is an incompatibility between the PCI Root Port and the device I am trying to use (an M.2 co-processor card). Any thoughts on why a particular PCIe device would not be detected, or what tools could provide more information? Is the following !!! Invalid class message significant? The device I am trying to attach has the following lspci verbose info on another platform: |
Beta Was this translation helpful? Give feedback.
-
|
root@icicle-kit-es:~# lspci Above output of lscpi is correct and expected. Above line is for the PCI Host Bridge, which is an internal controller, not an external PCIe slave device. A PCI host bridge provides an interconnect between the processor and peripheral components. Through the PCI host bridge, the processor can directly access main memory independent of other PCI bus masters. The output above '"lspci output" contains the following sections:- 00:00.0 - The bus number, device number, and function number, in that order. Hope this explain the lspci o/p you are seeing. |
Beta Was this translation helpful? Give feedback.
-
|
Pls ignore "!!! Invalid class 0006 for header type 01" message as it is benign. It has no impact for your M.2 device not getting enumerated. I hope you are using below steps to bring-up Linux on Icicle kit. Pls reprogram card with latest design file and latest Linux image, available here:- Just FYI, I sometime noticed, that my Icicle fail to enumerate my PCI device. Though it's rare. Here is what I do :-
Hope this helps. Thanks |
Beta Was this translation helpful? Give feedback.
-
|
@sanjeevb-bansal Thanks for your response. For me NVMe devices are detected 100% of the time in the carrier board but I have never seen the device I need to connect. I believe this responds to all of your suggestions. Good to know I can ignore the invalid class message. I will try pulling changes, rebuilding and seeing if any recent commits fix. |
Beta Was this translation helpful? Give feedback.
-
|
Whoa, I spoke too soon. Same distro, one reboot later and I am seeing the device. Any thoughts on why detection would be intermittent? Is this an electrical / connectivity issue? |
Beta Was this translation helpful? Give feedback.
-
|
Yes, on some rare kits we need to provide a support (a small raise below PCIe card) and might require one extra reboot based on my own observation on my own kit. It is probably because of horizontal mount of the PCIe card and hooks to tighten it ( unlike Desktop PC) |
Beta Was this translation helpful? Give feedback.
-
|
So after most of a day rebooting this thing, I found that the PCIe support for my device (a coprocessor M.2 module) worked once out of maybe 100 reboots, whereas an NVMe inserted in the same adapter board worked 100% of the time. Successive boots did a variety of the following:
Not sure what explains this wide variety of behavior, but various supports under the board and different insertion depths didn't seemed to make a consistent difference. Besides the rare connectivity issue, are you aware of any issues with the PCIe support on this platform, either at the RTL level or with the kernel support, which could explain this? Given than the NVMe operated consistently it appears that something other than connectivity must be an issue. |
Beta Was this translation helpful? Give feedback.
-
|
Hey @mcmordie any luck with this? One thing it would be interesting to see, when you get a failure to detect your drive, on the HSS console (MMUART0) could you run a DDR mem test, you just need to type |
Beta Was this translation helpful? Give feedback.
-
|
@hughbreslin no further progress yet. Here is a summary / reminder of what I see:
When the unit is failing to boot, this is the MEMTEST result: The card wiggling issue would be suggestive of a hardware issue-- for example out of spec lane length or impedance-- if the NVMe didn't work consistently. It would be nice to get to a place of understanding the issue better before our own board gets built. |
Beta Was this translation helpful? Give feedback.
-
|
Interesting, could you share which card you're using? I haven't gotten any closer to having a direct answer for you unfortunately. PCIe is something we're currently working on so it could be resolved in a future release but the fact that it works sometimes leads me to believe its something outside of what we're currently working on |
Beta Was this translation helpful? Give feedback.
-
|
@hughbreslin I can provide more info via email-- mcmordie at viionsystems.com |
Beta Was this translation helpful? Give feedback.
-
When I boot the mpfs-dev-cli image I am able to run lspci and see the following:
root@icicle-kit-es:~# lspci00:00.0 Unclassified device [0006]: Actel Device 1556However I do not see the PCIe device which I have attached to the board via J1. Should this automatically appear or is there something else I need to enable to get this working? Is there further documentation on the Linux support for the PCIe Root Port? The documentation I was able to find so far is here. This does not talk much about Linux software support.
Beta Was this translation helpful? Give feedback.
All reactions