FTDI Community

General Category => Discussion - Drivers => Topic started by: randomEngineer on September 18, 2020, 02:17:42 PM

Title: FT_GetDeviceDescriptor returns failure in Linux but not Windows
Post by: randomEngineer on September 18, 2020, 02:17:42 PM

Greetings everyone,

When using the Linux FTD3xx library (version 0.5.21) in Linux (Ubuntu 20.04 LTS), FT_GetDeviceDescriptor(ftHandle, &devDescriptor) returns a status of 4 (FT_IO_ERROR).  The function used to create the handle FT_Create(0, FT_OPEN_BY_INDEX, &ftHandle) returns 0 (FT_OK).  There is only one device detected by the devices (making the FT_Create unambiguous).  Despite returning an error, the function descriptor produces a vid and pid.  If the error is ignored, subsequent functions will also produce the same error.  The same code works in Windows. 

Here is the information about the device:

Device[0]
        Flags: 0x4 [USB 3] | Type: 600 | ID: 0x0403601E | ftHandle=0x53572e3b45534a2e
        SerialNumber=000000000001
        Description=FIFO Bridge (Windows)
        Description=FTDI SuperSpeed-FIFO Bridge (Linux)

Thank you

Title: Re: FT_GetDeviceDescriptor returns failure in Linux but not Windows
Post by: FTDI Community on September 23, 2020, 04:41:01 PM

Hello,

You are already in contact with our support team on this issue via email.
Please post any resolution here to help other customers

Best Regards,
FTDI Community

Title: Re: FT_GetDeviceDescriptor returns failure in Linux but not Windows
Post by: ionetrics on November 16, 2020, 11:14:50 PM

I have encountered this same exact problem.  I am also using Linux FTD3xx v0.5.21 and Ubuntu 20.04 LTS.  FT_GetDeviceDescriptor returns FT_IO_ERROR, but I found that I can use the generic form (FT_GetDescriptor) to get the device descriptor and it returns with FT_OK.  My device ID is 0x0403601F.

Title: Re: FT_GetDeviceDescriptor returns failure in Linux but not Windows
Post by: FTDI Community on November 19, 2020, 04:33:45 PM

Hello,

FT_IO_ERROR usually points to a hardware issue.

Please test with our known good hardware:

https://www.ftdichip.com/Products/Modules/SuperSpeedModules.htm (https://www.ftdichip.com/Products/Modules/SuperSpeedModules.htm)

Also reference our known good software:

https://www.ftdichip.com/Support/SoftwareExamples/FT60X.htm (https://www.ftdichip.com/Support/SoftwareExamples/FT60X.htm)

The post creator 'randomEngineer' may also be able to provide you with information from his original issue.

Best Regards,
FTDI Community