Hi,
i have some code thats based off of the uart_async_adapter.c example code. I'm getting a `usage fault` which i've traced to uart_irq_handler. it happens when i try to send a single byte 7F over the uart.
the strange thing is that after that fault it resets then it always works the second time.
uart_async_adapter.c: irq_handler
static void uart_irq_handler(const struct device *target_dev, void *context)
{
const struct device *dev = context;
struct uart_async_adapter_data *data = access_dev_data(dev);
__ASSERT(target_dev == data->target,
"IRQ handler called with a context that seems uninitialized.");
LOG_DBG("irq_handler: Enter");
if (uart_irq_update(target_dev) && uart_irq_is_pending(target_dev)) {
if (data->tx.enabled && uart_irq_tx_ready(target_dev)) {
on_tx_ready(dev, data);
}
if (data->tx.enabled && uart_irq_tx_complete(target_dev)) {
on_tx_complete(dev, data);
}
if (data->rx.enabled && uart_irq_rx_ready(target_dev)) {
on_rx_ready(dev, data);
}
/* Check errors only after all the data is received from the device */
int rx_err = uart_err_check(target_dev);
if (rx_err < 0) {
rx_err = 0;
}
if (data->rx.enabled && rx_err) {
on_error(dev, data, rx_err);
}
}
LOG_DBG("irq_handler: Exit");
}i get the "Notification: UART_RX_BUF_RELEASED" in the switch_rx_buffer() function, just before the crash.
- uart_irq_handler
- on_rx_ready(dev, data)
- switch_rx_buffer(dev, true)
- notify_rx_buffer_req(dev)
RTT Log:
D: tx(async_adapter, 0x2000b2dc, 1, -1) D: tx: sending D: irq_handler: Enter D: on_tx_ready: Enter(async_adapter) (left: 1) D: Pushed 1 characters D: on_tx_ready: Exit D: on_error: Enter(async_adapter) 12 D: Notification: UART_RX_BUF_RELEASED E: ***** USAGE FAULT ***** E: Illegal use of the EPSR E: r0/a1: 0x0003b348 r1/a2: 0x20009cd4 r2/a3: 0x00030102 E: r3/a4: 0x0000e100 r12/ip: 0x200053cc r14/lr: 0x0002174f E: xpsr: 0x60000012 E: Faulting instruction address (r15/pc): 0x0000e100 E: >>> ZEPHYR FATAL ERROR 35: Unknown error on CPU 0 E: Fault during interrupt handling
I modified the log_dbg message in the on_error() function to include the rx_err code, which is `12`. i think this means UART_ERROR_FRAMING & UART_BREAK
not sure if its because the other end of the uart (another mcu) is being configured to enable its uart, before sending the data, and so causing some noise. is there a way to basically clear any pending interrupts and rx buffer in the nrf device?
sorry hope that makes some sense, i can provide more details if needed.
many thanks,
michael.