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Commit 2c65a511 authored by Tudor Ambarus's avatar Tudor Ambarus Committed by Greg Kroah-Hartman
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tty: serial: atmel: Check return code of dmaengine_submit() 



[ Upstream commit 1e67bd2b8cb90b66e89562598e9c2046246832d3 ]

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: 08f738be ("serial: at91: add tx dma support")
Signed-off-by: default avatarTudor Ambarus <tudor.ambarus@microchip.com>
Acked-by: default avatarRichard Genoud <richard.genoud@gmail.com>
Link: https://lore.kernel.org/r/20211125090028.786832-3-tudor.ambarus@microchip.com


Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: default avatarSasha Levin <sashal@kernel.org>
parent 41cfcf37

drivers/tty/serial/atmel_serial.c

+10 −0
Original line number Diff line number Diff line
@@ -928,6 +928,11 @@ 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)
@@ -1186,6 +1191,11 @@ 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;