SM API: smGetDeviceList() & smNetworkConfigGetDeviceList() bug

[tschmitz]

Hello, I think I discovered a bug with device discovery.

When I run the following code with an SM200C connected (both USB-2.0 and 10GbE SFP+ connected), I get no devices found.

    int serial_numbers[SM_MAX_DEVICES], count;
    int net_serials[SM_MAX_DEVICES], net_count;
    int all_serials[SM_MAX_DEVICES * 2] = {0}, all_count = 0;

    SmStatus status = smGetDeviceList(serial_numbers, &count);
    LOG_DBG("Fetched %d serial numbers from <code>smGetDeviceList</code>", count);

    if (status != smNoError) {
        throw std::runtime_error(smGetErrorString(status));
    }

    status = smNetworkConfigGetDeviceList(net_serials, &net_count);
    LOG_DBG("Fetched %d serial numbers from <code>smNetworkConfigGetDeviceList</code>",
            net_count);

    if (status != smNoError) {
        throw std::runtime_error(smGetErrorString(status));
    }

    for (size_t i = 0; i < count; i++) {
        all_serials[all_count] = serial_numbers[i];
        all_count++;
    }

    for (size_t i = 0; i < net_count; i++) {
        all_serials[all_count] = net_serials[i];
        all_count++;
    }

I also found if I add a delay of roughly 1.5 seconds between the two API calls, it correctly finds the SM200C. Reversing the API calls also works, but I have a feeling that it breaks discovery for the SM200B/SM435B.

OS: Ubuntu 22.04
API Version: 2.3.8
C++ Standard: C++11
CPU: AMD Ryzen 9 9955HX

• This topic was modified 3 days, 1 hour ago by tschmitz. Reason: Additional info
• This topic was modified 3 days, 1 hour ago by tschmitz. Reason: Formatting

Thanks for pointing this out. I’ll make sure the software department sees this.

[Roger]

Hi tschmitz,

The issue appears to be that the net_count variable is uninitialized. The smNetworkConfigGetDeviceList function uses its pararameter deviceCount to determine how large the serials array is, so it can return a maximum of that many devices (zero in this case).

In other words, the second line of code should be: int net_serials[SM_MAX_DEVICES], net_count = SM_MAX_DEVICES;

I know it is odd that the seemingly equivalent function for USB devices (SM200B/SM435B) does not have this requirement.

Let me know if this doesn’t fix it.

– Roger

• This reply was modified 19 hours, 17 minutes ago by Roger.

Yup, that solved it! I probably should have consulted the documentation first…

[in,out]	deviceCount	Point to int that contains the size of the serials array. When the function returns it will contain the number of devices returned.

– Tom

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