Commit 29788ab1 authored Sep 29, 2020 by Peng Fan Committed by Greg Kroah-Hartman Sep 30, 2020

tty: serial: fsl_lpuart: fix lpuart32_poll_get_char



The watermark is set to 1, so we need to input two chars to trigger RDRF
using the original logic. With the new logic, we could always get the
char when there is data in FIFO.

Suggested-by: Fugang Duan <fugang.duan@nxp.com>
Signed-off-by: Peng Fan <peng.fan@nxp.com>
Link: https://lore.kernel.org/r/20200929095509.21680-1-peng.fan@nxp.com


Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

parent 9ea40db4

drivers/tty/serial/fsl_lpuart.c

+1 −1

Original line number	Diff line number	Diff line
		@@ -680,7 +680,7 @@ static void lpuart32_poll_put_char(struct uart_port *port, unsigned char c)

		static int lpuart32_poll_get_char(struct uart_port *port)
		{
		if (!(lpuart32_read(port, UARTSTAT) & UARTSTAT_RDRF))
		if (!(lpuart32_read(port, UARTWATER) >> UARTWATER_RXCNT_OFF))
		return NO_POLL_CHAR;

		return lpuart32_read(port, UARTDATA);

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