[4.14,50/75] serial: sh-sci: suppress warning for ports without dma channels
diff mbox series

Message ID 20171207130820.814318245@linuxfoundation.org
State New, archived
Headers show
  • 4.14.5-stable review
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Commit Message

Greg Kroah-Hartman Dec. 7, 2017, 1:08 p.m. UTC
4.14-stable review patch.  If anyone has any objections, please let me know.


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(+)

diff mbox series

--- 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_
 	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) {