uart_read_fifo() reads only 2 chars on nucleo STM32L43KC and nRF52840-DK

[Sergi22]

I'm trying to setup RX over UART in INTERRUPT_DRIVEN mode.

Here is my code:

#include <zephyr.h>

// #include <zephyr/types.h>
// #include <arch/cpu.h>
#include <string.h>
#include <sys/printk.h>
// #include <sys/util.h>

#include <drivers/uart.h>

static const struct device *uart1_dev;

typedef struct uart_data
{
    char * tx_data;
    char * rx_data;
    uint8_t tx_len;
    uint8_t rx_len;
    uint8_t rx_count;
}uart_data;

static void uart_cb(const struct device *uart_device, void *user_data)
{
    uart_data * uart1_data = (uart_data *)user_data;
    static int sent_len = 10;

    /* Verify uart_irq_update() */
	if (!uart_irq_update(uart_device)) {
		printk("retval should always be 1\r\n");
		return;
	}
 
    if (uart_irq_tx_ready(uart_device))
    {
        if(uart1_data->tx_len)
        {
            sent_len = uart_fifo_fill(uart_device, uart1_data->tx_data, (sent_len < uart1_data->tx_len) ? sent_len : uart1_data->tx_len);
            uart1_data->tx_len -= sent_len;
            uart1_data->tx_data += sent_len;
            printk("Sending data to UART1 with len %d\r\n", sent_len); 
        }
        else
        {
            uart_irq_tx_disable(uart1_dev);
        }
    }

    /* get all of the data off UART as fast as we can */
    if(uart_irq_rx_ready(uart_device)) 
    {
        uint8_t c;

        uart_fifo_read(uart_device, &c, 1) ;
        uart1_data->rx_count--;
        *uart1_data->rx_data++ = c;

        printk("Letter %c\r\n", c);

        if((c == '\n') || (uart1_data->rx_count == 0))
        {
            uart_irq_rx_disable(uart1_dev);
            uart1_data->rx_data -= (uart1_data->rx_len - uart1_data->rx_count);
            printk("Rcvd msg: %s", uart1_data->rx_data); 
            k_msleep(10);
            memset(uart1_data->rx_data, 0, uart1_data->rx_len);
            
            uart1_data->rx_count = uart1_data->rx_len;
            uart_irq_rx_enable(uart1_dev);
        } 
    }
}

void main(void)
{
    
    char test[21] = "Tx ISR working test\r\n";
    char test_rcv[40] = {0};
    uart1_dev = device_get_binding("UART_1");

    printk("Device ready %d\r\n", device_is_ready(uart1_dev));


    uart_data uart1_data = {test, test_rcv, 20, 40, 40};
    uart_irq_callback_user_data_set(uart1_dev, uart_cb, &uart1_data);

    uart_irq_tx_enable(uart1_dev);
    uart_irq_rx_enable(uart1_dev);

    while(1)
    {
        // printk("UART TX return code\r\n");
        k_msleep(2000);
    }

}

Basically what If get in the terminal when I try to send message over UART and print it with printk()

On Nordic it gets 1st and 7th letters, on STM32 it gets first letters.
Did anyone had similar issue ?

[erwango]

If both targets are impacted, this could be an API related usage issue.
@dcpleung would you mind having a look ?

[dcpleung]

Usage seems correct. I have tried the code with qemu_x86 and it worked fine without any missing characters (though would fault if I paste strings into it too fast).

Could you try running samples/subsys/shell/shell_module on those board? Also which commits are you using? If I remember correctly, there are couple PRs merged for fixing UART issues on both drivers.

[Sergi22]

Changed the code a bit and it started to work. Still not sure what the issue was. I was using platform IO to setup the project, may be it affected somehow. Not sure how to check exact commit from platform IO. But I see this line from build output:
PACKAGES:

• framework-zephyr 2.20500.210226 (2.5.0)

Changed callback code in case it is needed
`
static void uart_cb(const struct device *uart_device, void *user_data)
{
uart_data * uart1_data = (uart_data *)user_data;
static int sent_len = 10;
// static uint8_t len = (uart_data *)user_data;

/* Verify uart_irq_update() */
if (!uart_irq_update(uart_device)) {
	printk("retval should always be 1\r\n");
	return;
}
 
if (uart_irq_tx_ready(uart_device))
{
    if(uart1_data->tx_len)
    {
        sent_len = uart_fifo_fill(uart_device, uart1_data->tx_data, (sent_len < uart1_data->tx_len) ? sent_len : uart1_data->tx_len);
        uart1_data->tx_len -= sent_len;
        uart1_data->tx_data += sent_len;
        printk("Sending data to UART1 with len %d\r\n", sent_len); 
    }
    else
    {
        uart_irq_tx_disable(uart1_dev);
    }
}

/* get all of the data off UART as fast as we can */
if(uart_irq_rx_ready(uart_device)) 
{
    (void)uart_fifo_read(uart_device, uart1_data->rx_data++, 1);
    uart1_data->rx_count--;

    if((*(uart1_data->rx_data - 1) == '\r') || (uart1_data->rx_count == 0))
    {
        uart_irq_rx_disable(uart1_dev);
        uart1_data->rx_data -= (uart1_data->rx_len - uart1_data->rx_count);
        printk("\r\n");
        printk("%s\r\n", uart1_data->rx_data);     
        memset(uart1_data->rx_data, 0, uart1_data->rx_len);
        uart1_data->rx_count = uart1_data->rx_len;
        uart_irq_rx_enable(uart1_dev);
    }
}

}`
Closing this issue.

[erwango]

@Sergi22 thanks for feedback.