The tx_submit() method of struct dma_async_tx_descriptor is entitled
to do sanity checks and return errors if encountered. It's not the
case for the DMA controller drivers that this client is using
(at_h/xdmac), because they currently don't do sanity checks and always
return a positive cookie at tx_submit() method. In case the controller
drivers will implement sanity checks and return errors, print a message
so that the client will be informed that something went wrong at
tx_submit() level.
Fixes: 08f738be88bb ("serial: at91: add tx dma support")
Signed-off-by: Tudor Ambarus <tudor.ambarus@xxxxxxxxxxxxx>
Acked-by: Richard Genoud <richard.genoud@xxxxxxxxx>
---
drivers/tty/serial/atmel_serial.c | 10 ++++++++++
1 file changed, 10 insertions(+)
diff --git a/drivers/tty/serial/atmel_serial.c b/drivers/tty/serial/atmel_serial.c
index 2c99a47a2535..376f7a9c2868 100644
--- a/drivers/tty/serial/atmel_serial.c
+++ b/drivers/tty/serial/atmel_serial.c
@@ -1004,6 +1004,11 @@ static void atmel_tx_dma(struct uart_port *port)
desc->callback = atmel_complete_tx_dma;
desc->callback_param = atmel_port;
atmel_port->cookie_tx = dmaengine_submit(desc);
+ if (dma_submit_error(atmel_port->cookie_tx)) {
+ dev_err(port->dev, "dma_submit_error %d\n",
+ atmel_port->cookie_tx);
+ return;
+ }
}
if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
@@ -1258,6 +1263,11 @@ static int atmel_prepare_rx_dma(struct uart_port *port)
desc->callback_param = port;
atmel_port->desc_rx = desc;
atmel_port->cookie_rx = dmaengine_submit(desc);
+ if (dma_submit_error(atmel_port->cookie_rx)) {
+ dev_err(port->dev, "dma_submit_error %d\n",
+ atmel_port->cookie_rx);
+ goto chan_err;
+ }
return 0;
--
2.25.1
