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authorPeter Hurley <peter@hurleysoftware.com>2016-04-09 22:14:33 -0700
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2016-04-30 09:26:55 -0700
commitddedfd82bc61c8d8d4d0eb754a9bcebb2e84de75 (patch)
tree149e9e339cb29f788e657384670eaca0da0648ed /drivers/tty
parentec5a11a91eecd81ef19b8044a243b4ea56c809e6 (diff)
downloadlinux-ddedfd82bc61c8d8d4d0eb754a9bcebb2e84de75.tar.bz2
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>
Diffstat (limited to 'drivers/tty')
-rw-r--r--drivers/tty/serial/8250/8250_dma.c9
1 files changed, 9 insertions, 0 deletions
diff --git a/drivers/tty/serial/8250/8250_dma.c b/drivers/tty/serial/8250/8250_dma.c
index cf7a2e3288a6..7a26c4d13b18 100644
--- a/drivers/tty/serial/8250/8250_dma.c
+++ b/drivers/tty/serial/8250/8250_dma.c
@@ -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 */