CC3135: How to port simplelink drivers to a non-TI platform?

I've gotten it to work but can't get speeds more than 40KiBps. I suspect it has to do with how I'm calling sl_Task. The driver is set to be in non-rtos mode. I create a new thread at startup that will keep on calling the sl_Task function. In the main thread i call the rest of the sl_Start -> sl_Connect -> sl_Send functions. With a TCP server running on my PC, the max speed that it can get is 40 KiBps. If i put it in AP mode and curl the inbuilt HTTP server i can get around 250KiBps. The host is a STM32 L476 Nucleo board. What speed can be expected on a 2.5GHz access point?

Hello,

The max data throughput listed in the CC3135 datasheet is 16 Mbps UDP and 13 Mbps TCP, but this is assuming your host driver layer is also at max throughput. Depending on how often you are calling sl_Task, this may be where you're bottlenecking.

Why are you calling sl_Task in a thread instead of using the RTOS directly with the driver? What is the priority of the thread calling sl_Task?

This E2E post may be helpful to explain how we measure throughput in our tests: e2e.ti.com/.../733986

Best regards,

Sarah

>Why are you calling sl_Task in a thread instead of using the RTOS directly with the driver

The driver was calling posix APIs which my RTOS did not provide. Ive now made the required changes and now its running the SL_PLATFORM_MULTI_THREADED version of the driver but still the performance is exactly the same.

>What is the priority of the thread calling sl_Task

Its set to higher priority than the main thread. Also unless i call yield() (or a printf) after sl_Send(), it sends a few KiBs and then stalls. Maybe there is something in sl_Send() that is causing the sl_Task() to starve.

Hello,

Can you share how you are calling sl_Send()? Can you test the network_terminal example and compare the behavior?

Best regards,

Sarah

Here is the code that i used

#include "mbed.h"
#include "ti/drivers/net/wifi/device.h"
#include "ti/drivers/net/wifi/sl_socket.h"
#include "ti/net/slneterr.h"
#include "ti/net/slnetsock.h"

void runSlTask()
{
        sl_Task(nullptr);
}

int main()
{
        Thread thread;
        thread.set_priority(osPriorityHigh);
        thread.start(callback(runSlTask));

        DigitalOut led(LED1);
        DigitalOut nReset(PC_8, false);
        ThisThread::sleep_for(500);
        nReset = true;

        printf("==============\r\n");

        auto result = sl_Start(nullptr, nullptr, nullptr);
        const auto sockid = sl_Socket(SL_AF_INET, SL_SOCK_STREAM, 0);

        constexpr SlTimeval_t timeVal{ 20, 0 };

        auto sockOptSetResult = sl_SetSockOpt(sockid, SL_SOL_SOCKET, SL_SO_RCVTIMEO, &timeVal, sizeof(timeVal));
        if (sockOptSetResult != 0) {
                printf("ERR\r\n");
                NVIC_SystemReset();
        }
        constexpr SlSockNonblocking_t enableOption{ 1 };

        sockOptSetResult = sl_SetSockOpt(sockid, SL_SOL_SOCKET, SL_SO_NONBLOCKING, (_u8 *)&enableOption, sizeof(enableOption));
        if (sockOptSetResult != 0) {
                printf("ERR\r\n");
                NVIC_SystemReset();
        }

        SlSockAddrIn_t addr;
        addr.sin_family = SL_AF_INET;
        addr.sin_port = sl_Htons(8888);

        addr.sin_addr.s_addr = sl_Htonl(SL_IPV4_VAL(192, 168, 42, 130));

        result = SLNETERR_BSD_EALREADY;

        constexpr auto POLL_INTERVAL = 2;
        constexpr auto MAX_POLL = 20000;
        constexpr auto MAX_POLL_CONNECT = MAX_POLL;

        for (int i = 0; i < MAX_POLL_CONNECT && result == SLNETERR_BSD_EALREADY; i++) {
                result = sl_Connect(sockid, reinterpret_cast<SlSockAddr_t *>(&addr), sizeof(SlSockAddrIn_t));
                ThisThread::yield();
                if (result < 0) {
                        ThisThread::sleep_for(POLL_INTERVAL);
                }
        }

        if (result < 0) {
                printf("Failed to connect %d\n", result);
                NVIC_SystemReset();
        }

        constexpr auto BUFFER_SIZE = 1 * 1024;
        static char buffer[BUFFER_SIZE];
        std::transform(std::begin(buffer), std::end(buffer), std::begin(buffer),
                       [](char) -> char { return static_cast<char>(std::rand()); });

        for (int i = 0; i < 1024 * 1024; i++) {
                result = SLNETERR_BSD_EAGAIN;
                for (int k = 0; k < MAX_POLL && result == SLNETERR_BSD_EAGAIN; k++) {
                        {
                                result = sl_Send(sockid, buffer, sizeof(buffer), 0);
                        }
                        if (result != sizeof(buffer)) {
                                ThisThread::sleep_for(POLL_INTERVAL);
                        } else {
                                led = !led;
                        }
                }
                ThisThread::yield();

                if (result < 0) {
                        printf("Failed to send%d\n", result);
                        NVIC_SystemReset();
                }
        }

        sl_Close(sockid);
        sl_Stop(0xFFFF);
}

Hello,

Can you clarify what behavior you mean when send stalls? Do you see some packets sent correctly and then no more are sent? Or are you stepping through your code and see a function hanging?

Please be sure that you have that latest servicepack version flashed.

Best regards,

Sarah