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  Message 1 of 2  
06 Oct 17 08:54
Mark Bewley
xxxxxx@gbelectronics.com
Join Date: 26 Sep 2017
Posts To This List: 6
UMDF to KMDF driver communication; best practice?

What is the best way to communicate between a UMDF v2 driver and a KMDF driver? I have a functional KMDF USB driver that I can do ReadFile and WriteFile on. I am attempt to keep the kernel driver as simple as possible. To work with a legacy application I have a separate UMDF v2 Virtual COM Port (VCP) driver. This will contain any buffering; implement the WaitOnEvent and the other stuff specific to COM ports. Another reason for splitting the driver is so the COM port remains present when the USB device is not attached. Should I be using CreateFile, ReadFile and WriteFile in the UMDF v2 driver using overlapped I/O, as I would do when writing applications; or a different approach? I have read older discussions and documentation online, but either about kernel drivers or UMDF v1. Not entirely sure what is valid, or appropriate, for UMDF v2. Thanks, Mark
  Message 2 of 2  
06 Oct 17 10:01
Peter Viscarola (OSR)
xxxxxx@osr.com
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Posts To This List: 5949
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UMDF to KMDF driver communication; best practice?

<quote> Should I be using CreateFile, ReadFile and WriteFile in the UMDF v2 driver using overlapped I/O, as I would do when writing applications; or a different approach? </quote> If what you want to do are well-patterned as reads and writes, then yes... this is the right thing to do. Alternatively, you can use the famous "inverted call model": <https://www.osr.com/nt-insider/2013-issue1/inverted-call-model-kmdf/> Peter OSR @OSRDrivers
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