drivers: serial: litex: remove redundant rx pending

flushing rx pending already happens in
uart_litex_fifo_read, which should be called
by the callback, so don't do it again, also
it can lead to the drop of chars, as flushing
removes the current entry in the fifo.

Signed-off-by: Fin Maaß <[email protected]>

Author: maass-hamburg

drivers/serial/uart_litex.c

@@ -267,19 +267,13 @@ static void uart_litex_irq_callback_set(const struct device *dev,
 
 static void uart_litex_irq_handler(const struct device *dev)
 {
-	const struct uart_litex_device_config *config = dev->config;
 	struct uart_litex_data *data = dev->data;
 	unsigned int key = irq_lock();
 
 	if (data->callback) {
 		data->callback(dev, data->cb_data);
 	}
 
-	/* Clear RX events, TX events still needed to enqueue the next transfer */
-	if ((litex_read8(config->ev_pending_addr) & UART_EV_RX) > 0) {
-		litex_write8(UART_EV_RX, config->ev_pending_addr);
-	}
-
 	irq_unlock(key);
 }
 #endif	/* CONFIG_UART_INTERRUPT_DRIVEN */