Wrong IRQ triggered for AMT SOL on NUC5i5MYHE?

MPart3 · ‎10-04-2017

I am experiencing problems using the AMT SOL feature on a NUC5i5MYHE. Here's the symptom:

Windows 7 just hangs when using the port (e.g., using PowerShell). If I configure a timeout, I just get the timeout, but no serial output.
Linux experiences a long delay after printing the characters, but it also complains about unexpected interrupts. Using the "irqpoll" cmdline option, it works fine.
A baremetal kernel works fine without interrupts, and even the interrupt-driven configuration works if you find the correct interrupt to use.

Interestingly, the interrupt that both Linux and Windows report (17) does not match the actual one that can be observed (19). Furthermore, IRQ 19 is also the SATA interrupt, which makes me wonder if 17 is actually the correct one, but for some reason it is not being used.

This happens on several machines of this model, and I have tried multiple BIOS versions, including the most recent one (86A.0038).

Has anyone else seen this? I would really appreciate some help

idata · ‎10-04-2017

Hello parthy,

Thank you for joining the Intel® NUC Community. I am sorry to hear you are having issues with this feature.

Please let me review this matter, I will update the thread as soon as possible.

Regards,

Amy C.

Ronny_G_Intel · ‎10-06-2017

Hello /thread/118412 parthy,

I work for Intel Customer Support but I am not an expert on vPRO* or AMT* so I would recommend that you post this question to: they would be able to help you better than in this forum.

Just one more additional comment: Are you using any sort of management console? Intel AMT can use a virtual serial port but it is virtual and the OS sees it as a serial port, a management console securely connected to Intel® AMT using the Ethernet port so that it can send and receive data to this virtual serial port. If no management software is connected, the data sent to the serial port is simply lost.

Regards,

Ronny G

MPart3 · ‎10-06-2017

Hi,

thanks for the hint, I posted the question there.

The issue is not that the output is lost, I have a terminal connected via AMT. The issue is that the output command hangs, presumably because it's waiting for an IRQ that never happens.

Best

Markus