From 7464779fa8551b90d5797d4020b0bdb7e6422eb9 Mon Sep 17 00:00:00 2001 From: Andy Lowe Date: Fri, 22 Sep 2017 20:29:30 +0200 Subject: [PATCH] serial: sh-sci: suppress warning for ports without dma channels 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 Signed-off-by: Eugeniu Rosca Signed-off-by: Greg Kroah-Hartman --- drivers/tty/serial/sh-sci.c | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/drivers/tty/serial/sh-sci.c b/drivers/tty/serial/sh-sci.c index 41bf9103ed3f..9fde3df1b3a8 100644 --- a/drivers/tty/serial/sh-sci.c +++ b/drivers/tty/serial/sh-sci.c @@ -1506,6 +1506,14 @@ static void sci_request_dma(struct uart_port *port) 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) {