From: Tudor Ambarus tudor.ambarus@microchip.com
[ 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: 08f738be88bb ("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.co... Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org Signed-off-by: Sasha Levin sashal@kernel.org --- 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 936d401f20b95..f6287d76b2984 100644 --- a/drivers/tty/serial/atmel_serial.c +++ b/drivers/tty/serial/atmel_serial.c @@ -918,6 +918,11 @@ 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) @@ -1176,6 +1181,11 @@ 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;