mPCI Express Power Cycle

dhu
dhu New Member Posts: 23
I tried system reboot of the Upsqaure as well as mPCI reset echo "1" > /sys/bus/pci/devices/DDDD\:BB\:DD.F/remove
PCIe Reset/Powercycle without reboot
In both cases only the USB bus attached to the PCI is reset. But the mini PCI Express itself does not do powercycle. I see the voltage at 3.3V with voltmeter for all the cases.
Secondly even after a shutdown the mPCI Express power line is up.
Is there way to power cycle the mPCI Express? Does anyone know any other method to Power Cycle mPCI Express.

Comments

  • rogertsai(AAEON)
    rogertsai(AAEON) New Member Posts: 350 ✭✭✭
    edited October 2017
    Let me clarify your question. Are you asking could mPCI(CN8) full power-off and using a shutdown as SW/HW for your device?
    If that was your question, the answer is no. this UP2 architecture is for desktop (AC mode), not for mobile, so always have some power on the board
    If you looking for HW reset for your application, the mPCI(CN8) support to HW reset with system reboot, if your device support HW reset pin
    What kind of device do you use to connect the mPCI? your linux version is ?
  • dhu
    dhu New Member Posts: 23
    Hardware:
    UP Squared: 2G/32 GB variant
    OS: SuSE Linux SLED 12-SP2, Kernel: 4.4.21
    mPCI: We connect the 4G PLS8/3G Quectel 3G U20 module. Both modules you can issue AT commands and connect to network

    Requirement: We need to do power cycle on mPCI slot on UP Square when we use in our system. This means the voltage to the mPCI drops to zero via reset and the mPCI is back online.
    If you looking for HW reset for your application, the mPCI(CN8) support to HW reset with system reboot, if your device support HW reset pin
    Can you clarify this more in details?
  • rogertsai(AAEON)
    rogertsai(AAEON) New Member Posts: 350 ✭✭✭
    edited October 2017
    If you looking for HW reset for your application, the mPCI(CN8) support to HW reset with system reboot, if your device support HW reset pin
    Can you clarify this more in details?

    The Mini PCI-e slot have supported in hardware reset feature, and reset with the system.
    In my experience some of the module can't support to HW reset, and only turn on/off the power.
    Could you check your 4G / 3G module is support it, or not?