Commit 2490a0ca authored by Amelie Delaunay's avatar Amelie Delaunay Committed by Greg Kroah-Hartman
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serial: stm32: synchronize RX DMA channel in shutdown 



In shutdown, RX DMA channel is terminated. If the DMA RX callback is
scheduled but not yet executed, while a new RX DMA transfer is started, the
callback can be executed, and then disturb the ongoing RX DMA transfer.
To avoid such a case, call dmaengine_synchronize in shutdown, after the
DMA RX channel is terminated.

Signed-off-by: default avatarAmelie Delaunay <amelie.delaunay@foss.st.com>
Signed-off-by: default avatarValentin Caron <valentin.caron@foss.st.com>
Link: https://lore.kernel.org/r/20230808161906.178996-7-valentin.caron@foss.st.com


Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent a01ae50d

drivers/tty/serial/stm32-usart.c

+3 −1
Original line number Diff line number Diff line
@@ -1123,8 +1123,10 @@ static void stm32_usart_shutdown(struct uart_port *port) 
		dev_err(port->dev, "Transmission is not complete\n");



	/* Disable RX DMA. */

	if (stm32_port->rx_ch)

	if (stm32_port->rx_ch) {

		stm32_usart_rx_dma_terminate(stm32_port);

		dmaengine_synchronize(stm32_port->rx_ch);

	}



	/* flush RX & TX FIFO */

	if (ofs->rqr != UNDEF_REG)