From: Tudor Ambarus tudor.ambarus@microchip.com
stable inclusion from stable-v5.10.94 commit 755a6c873b9c2e092ab6055cd116b1d8228ac34b bugzilla: https://gitee.com/openeuler/kernel/issues/I531X9
Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=...
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[ 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 Signed-off-by: Zheng Zengkai zhengzengkai@huawei.com Acked-by: Xie XiuQi xiexiuqi@huawei.com --- 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 a24e5c2b30bc..396fe8c51f93 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) @@ -1264,6 +1269,11 @@ 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;