--- /dev/null
+From 1980860e0c8299316cddaf0992dd9e1258ec9d88 Mon Sep 17 00:00:00 2001
+From: =?UTF-8?q?Ilpo=20J=C3=A4rvinen?= <ilpo.jarvinen@linux.intel.com>
+Date: Tue, 8 Nov 2022 14:19:52 +0200
+Subject: serial: 8250: Flush DMA Rx on RLSI
+MIME-Version: 1.0
+Content-Type: text/plain; charset=UTF-8
+Content-Transfer-Encoding: 8bit
+
+From: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
+
+commit 1980860e0c8299316cddaf0992dd9e1258ec9d88 upstream.
+
+Returning true from handle_rx_dma() without flushing DMA first creates
+a data ordering hazard. If DMA Rx has handled any character at the
+point when RLSI occurs, the non-DMA path handles any pending characters
+jumping them ahead of those characters that are pending under DMA.
+
+Fixes: 75df022b5f89 ("serial: 8250_dma: Fix RX handling")
+Cc: <stable@vger.kernel.org>
+Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
+Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
+Link: https://lore.kernel.org/r/20221108121952.5497-5-ilpo.jarvinen@linux.intel.com
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+---
+ drivers/tty/serial/8250/8250_port.c | 3 +--
+ 1 file changed, 1 insertion(+), 2 deletions(-)
+
+--- a/drivers/tty/serial/8250/8250_port.c
++++ b/drivers/tty/serial/8250/8250_port.c
+@@ -1869,10 +1869,9 @@ static bool handle_rx_dma(struct uart_82
+ if (!up->dma->rx_running)
+ break;
+ /* fall-through */
++ case UART_IIR_RLSI:
+ case UART_IIR_RX_TIMEOUT:
+ serial8250_rx_dma_flush(up);
+- /* fall-through */
+- case UART_IIR_RLSI:
+ return true;
+ }
+ return up->dma->rx_dma(up);