[En-Nut-Discussion] AT91SAM7X-EK, UART messing up the NutSleep

[Jix Electronics]

Hi,

I run to problems with uart, seems that devices DEV_UART and DEV_DEBUG
does not
work properly, tested with version 4.1.9-rc5.

When example code (below) is compiled with DEV_UART device. The first
NutSleep
call works correctly before registering the device. Second NutSleep waits
just
zero ticks, after that seems to work correctly.

example code print output:

(10)start=0, stop=10  --> 10
(10)start=41, stop=41 --> 0
(5)start=41, stop=46  --> 5
(1)start=46, stop=47  --> 1


When example code is compiled with DEV_DEBUG device, the first NutSleep works
correctly. All NutSleep calls after registering the device waits less than
asked for.

example code print output:

(10)start=0, stop=10  --> 10
(10)start=12, stop=20 --> 8
(5)start=22, stop=25  --> 3
(1)start=27, stop=27  --> 0


Modified threads example code
-----------------------------
int main(void)
{
    u_long baud = 115200;
    u_long start;
    u_long stop;

    start = NutGetTickCount();
    NutSleep(10);
    stop = NutGetTickCount();

    /*
     * Register the UART device, open it, assign stdout to it and set
     * the baudrate.
     */
    NutRegisterDevice(&DEV_DEBUG, 0, 0);
    freopen(DEV_DEBUG_NAME, "w", stdout);
    _ioctl(_fileno(stdout), UART_SETSPEED, &baud);

    printf("\n(10)start=%lu, stop=%lu\t--> %lu", start, stop, stop-start);

    start = NutGetTickCount();
    NutSleep(10);
    stop = NutGetTickCount();
    printf("\n(10)start=%lu, stop=%lu\t--> %lu", start, stop, stop-start);

    start = NutGetTickCount();
    NutSleep(5);
    stop = NutGetTickCount();
    printf("\n(5)start=%lu, stop=%lu\t--> %lu", start, stop, stop-start);

    start = NutGetTickCount();
    NutSleep(1);
    stop = NutGetTickCount();
    printf("\n(1)start=%lu, stop=%lu\t--> %lu", start, stop, stop-start);

    /*
     * Start two additional threads. All threads are started with
     * priority 64.
     */
    NutThreadCreate("t1", Thread1, 0, 512);
    NutThreadCreate("t2", Thread2, 0, 512);

    putchar('\n');
    putchar('\n');
    putchar('\r');

    /*
     * Endless loop in main thread.
     */
    for (;;) {
        putchar('M');
        NutSleep(125);
    }
}

Jix