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How does Hotplug work RRS feed

  • Question

  • Hi

    Can anybody please suggest me, How does Hotplug to device work ?

    Can you please provide any msdn link  ?

    Mrutyunjaya

    Friday, April 26, 2019 11:31 AM

Answers

  • As you can see in Device Manager, there's the Monitor class. Monitors are enumerated like other devices by their parent drivers, the video adapters. Most modern monitors contain their PnP info in a I2C EEPROM. The video driver detects connection of a monitor by some pin in the connector, like with USB. Then it reads this eeprom and gets all details.

    -- pa


    • Edited by Pavel A Friday, April 26, 2019 4:36 PM
    • Marked as answer by MRUTYUNJAYA.M Thursday, May 2, 2019 5:45 AM
    Friday, April 26, 2019 4:32 PM

All replies

  • Well the question is what do you mean by work?   Since you are asking about MSDN I am assuming you mean how does the OS respond and install the correct driver.   Basically, the bus driver for the bus you are plugging the device in determines that there is a new device and call IoInvalidateDeviceRelations to cause an IRP_MJ_PNP/IRP_MN_QUERY_DEVICE_RELATIONS https://docs.microsoft.com/en-us/windows-hardware/drivers/kernel/irp-mn-query-device-relations to be called.   The bus driver then indicates there is a new device, and the PnP manager calls various IRP_MJ_PNP calls to get the information it needs to determine what driver to load based on the INF files installed on the system.


    Don Burn Windows Driver Consulting Website: http://www.windrvr.com

    Friday, April 26, 2019 4:03 PM
  • Interms of work, I was asking about display hotplug detection. How does it work ?

    mrutyunjaya

    Friday, April 26, 2019 4:07 PM
  • As you can see in Device Manager, there's the Monitor class. Monitors are enumerated like other devices by their parent drivers, the video adapters. Most modern monitors contain their PnP info in a I2C EEPROM. The video driver detects connection of a monitor by some pin in the connector, like with USB. Then it reads this eeprom and gets all details.

    -- pa


    • Edited by Pavel A Friday, April 26, 2019 4:36 PM
    • Marked as answer by MRUTYUNJAYA.M Thursday, May 2, 2019 5:45 AM
    Friday, April 26, 2019 4:32 PM