Serial Port Driver

NTDEV
1

Good Morning,

I am have some trouble with a serial port driver. We have a driver created to utilize a pair of HSUARTS coming directly off of Apollo Lake Atom CPU. Everything work functions properly when using TeraTerm, but when I try to open the port using the .NET framwork (SerialPort.Open()), it complains that the attached device is not functioning properly. I’m assuming this is a driver issue because when I look at the IRP_MJ_DEVICE_CONTROL return when getting the properties, ProvSubType is unspecifiec (image link https://imgur.com/a/fVOokXp). I have zero driver experience and am looking for recommendations on how to go about troubleshooting this. Any assistance would be greatly appreciated.

Thanks.

2

I’m assuming this is a driver issue because when I look at the IRP_MJ_DEVICE_CONTROL return when getting the properties, ProvSubType is unspecifiec

Why do you assume that? I mean… why this SPECIFIC assumption?

I think this is unlikely to be a driver bug.

The Provider SubType being “unspecified” looks to me to be entirely legitimate.

Isn’t the source code for SerialPort.Open() publicly available? ISTR lots of assumptions and weirdness with this C# class.

Peter

3

(Sorry to FUP my own post…)

Yes… the Serial Port class source code IS available publicly. So… sounds like a debugging session is in order for the OP.

Peter