Missing UART event XUARTPS_EVENT_SENT_DATA when transmitting

[alfedotov]

I'm experiencing issue when transmitting reasonable amount of data using interrupt driven UART. In general it is working but sometimes (sporadically) it looks like missing final UART interrupt (I guess XUARTPS_IXR_TXEMPTY) when sending last chunk. Therefore I never get XUARTPS_EVENT_SENT_DATA event.

Can anybody explain why there is check for RX interrupts in following code of function XUartPs_SendBuffer:

https://github.com/Xilinx/embeddedsw/blob/836d748f91eda280bac23d0200df8a3bef61c0c3/XilinxProcessorIPLib/drivers/uartps/src/xuartps.c#L390

	if (((ImrRegister & XUARTPS_IXR_RXFULL) != (u32)0) ||
		((ImrRegister & XUARTPS_IXR_RXEMPTY) != (u32)0)||
		((ImrRegister & XUARTPS_IXR_RXOVR) != (u32)0)) {

		XUartPs_WriteReg(InstancePtr->Config.BaseAddress,
					   XUARTPS_IER_OFFSET,
					   ImrRegister | (u32)XUARTPS_IXR_TXEMPTY);
	}