Patch "serial: sh-sci: suppress warning for ports without dma channels" has been added to the 4.14-stable tree

Patch "serial: sh-sci: suppress warning for ports without dma channels" has been added to the 4.14-stable tree

[gregkh]

This is a note to let you know that I've just added the patch titled

    serial: sh-sci: suppress warning for ports without dma channels

to the 4.14-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     serial-sh-sci-suppress-warning-for-ports-without-dma-channels.patch
and it can be found in the queue-4.14 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.


>From foo@baz Wed Dec  6 18:04:41 CET 2017
From: Andy Lowe <andy_lowe@mentor.com>
Date: Fri, 22 Sep 2017 20:29:30 +0200
Subject: serial: sh-sci: suppress warning for ports without dma channels

From: Andy Lowe <andy_lowe@mentor.com>


[ Upstream commit 7464779fa8551b90d5797d4020b0bdb7e6422eb9 ]

If a port has no dma channel defined in the device tree, then
don't attempt to allocate a dma channel for the port.
Also suppress the warning message concerning the failure to allocate
a dma channel.  Continue to emit the warning message if a dma
channel is defined but cannot be allocated.

Signed-off-by: Andy Lowe <andy_lowe@mentor.com>
Signed-off-by: Eugeniu Rosca <erosca@de.adit-jv.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <alexander.levin@verizon.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 drivers/tty/serial/sh-sci.c |    8 ++++++++
 1 file changed, 8 insertions(+)

--- a/drivers/tty/serial/sh-sci.c
+++ b/drivers/tty/serial/sh-sci.c
@@ -1491,6 +1491,14 @@ static void sci_request_dma(struct uart_
 		return;
 
 	s->cookie_tx = -EINVAL;
+
+	/*
+	 * Don't request a dma channel if no channel was specified
+	 * in the device tree.
+	 */
+	if (!of_find_property(port->dev->of_node, "dmas", NULL))
+		return;
+
 	chan = sci_request_dma_chan(port, DMA_MEM_TO_DEV);
 	dev_dbg(port->dev, "%s: TX: got channel %p\n", __func__, chan);
 	if (chan) {


Patches currently in stable-queue which might be from andy_lowe@mentor.com are

queue-4.14/serial-sh-sci-suppress-warning-for-ports-without-dma-channels.patch