Commit ddedfd82 authored Apr 09, 2016 by Peter Hurley Committed by Greg Kroah-Hartman Apr 30, 2016

serial: 8250: Validate dmaengine tx chan meets requirements



8250 dma support requires the dmaegine driver support terminate.
Query slave caps to determine if necessary commands/properties are
supported; disable dma if not.

Note this means dmaengine driver must support slave caps reporting
as well.

Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Reviewed-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

parent ec5a11a9

drivers/tty/serial/8250/8250_dma.c

+9 −0

Original line number	Diff line number	Diff line
		@@ -201,6 +201,15 @@ int serial8250_request_dma(struct uart_8250_port *p)
		goto release_rx;
		}

		/* 8250 tx dma requires dmaengine driver to support terminate */
		ret = dma_get_slave_caps(dma->txchan, &caps);
		if (ret)
		goto err;
		if (!caps.cmd_terminate) {
		ret = -EINVAL;
		goto err;
		}

		dmaengine_slave_config(dma->txchan, &dma->txconf);

		/* RX buffer */