From 8cac2f6eb8548245e6f8fb893fc7f2a714952654 Mon Sep 17 00:00:00 2001 From: Michael Walle Date: Wed, 12 May 2021 16:12:55 +0200 Subject: [PATCH] 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: Michael Walle Link: https://lore.kernel.org/r/20210512141255.18277-10-michael@walle.cc Signed-off-by: Greg Kroah-Hartman --- drivers/tty/serial/fsl_lpuart.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/drivers/tty/serial/fsl_lpuart.c b/drivers/tty/serial/fsl_lpuart.c index 0d4eb02..508128d 100644 --- a/drivers/tty/serial/fsl_lpuart.c +++ b/drivers/tty/serial/fsl_lpuart.c @@ -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; -- 2.7.4