tty: serial: atmel: Check return code of dmaengine_submit()

[ Upstream commit 1e67bd2b8c ]

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: 08f738be88 ("serial: at91: add tx dma support")
Signed-off-by: Tudor Ambarus <tudor.ambarus@microchip.com>
Acked-by: Richard Genoud <richard.genoud@gmail.com>
Link: https://lore.kernel.org/r/20211125090028.786832-3-tudor.ambarus@microchip.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
This commit is contained in:
Tudor Ambarus 2021-11-25 11:00:17 +02:00 committed by Greg Kroah-Hartman
parent 06d6f69687
commit cd867ffa14

View file

@ -1002,6 +1002,11 @@ 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)
@ -1262,6 +1267,11 @@ 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;