Commit 8cac2f6e authored by Michael Walle's avatar Michael Walle Committed by Greg Kroah-Hartman
Browse files

serial: fsl_lpuart: disable DMA for console and fix sysrq 



SYSRQ doesn't work with DMA. This is because there is no error
indication whether a symbol had a framing error or not. Actually,
this is not completely correct, there is a bit in the data register
which is set in this case, but we'd have to read change the DMA access
to 16 bit and we'd need to post process the data, thus make the DMA
pointless in the first place.

Signed-off-by: default avatarMichael Walle <michael@walle.cc>
Link: https://lore.kernel.org/r/20210512141255.18277-10-michael@walle.cc


Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 8a0c810d

drivers/tty/serial/fsl_lpuart.c

+6 −0
Original line number Diff line number Diff line
@@ -1587,6 +1587,9 @@ static void lpuart_tx_dma_startup(struct lpuart_port *sport) 
	u32 uartbaud;

	int ret;



	if (uart_console(&sport->port))

		goto err;



	if (!sport->dma_tx_chan)

		goto err;
@@ -1616,6 +1619,9 @@ static void lpuart_rx_dma_startup(struct lpuart_port *sport) 
	int ret;

	unsigned char cr3;



	if (uart_console(&sport->port))

		goto err;



	if (!sport->dma_rx_chan)

		goto err;