From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: <> From: "George G. Davis" Subject: [PATCH] serial: sh-sci: disable DMA for uart_console Date: Thu, 9 May 2019 10:43:30 -0400 Message-Id: <1557413011-1662-1-git-send-email-george_davis@mentor.com> In-Reply-To: <20190506194233.GA32430@vmlxhi-102.adit-jv.com> References: <20190506194233.GA32430@vmlxhi-102.adit-jv.com> To: Eugeniu Rosca , Geert Uytterhoeven , Greg Kroah-Hartman , Jiri Slaby , "open list:SERIAL DRIVERS" , open list Cc: Simon Horman , Chris Brandt , Wolfram Sang , Ulrich Hecht , Andy Lowe , Linux-Renesas , OPEN FIRMWARE AND FLATTENED DEVICE TREE BINDINGS , Magnus Damm , Rob Herring , Mark Rutland , "George G. Davis" List-ID: As noted in commit 84b40e3b57ee ("serial: 8250: omap: Disable DMA for console UART"), UART console lines use low-level PIO only access functions which will conflict with use of the line when DMA is enabled, e.g. when the console line is also used for systemd messages. So disable DMA support for UART console lines. Fixes: https://patchwork.kernel.org/patch/10929511/ Reported-by: Michael Rodin Cc: Eugeniu Rosca Signed-off-by: George G. Davis --- drivers/tty/serial/sh-sci.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/drivers/tty/serial/sh-sci.c b/drivers/tty/serial/sh-sci.c index 3cd139752d3f..885b56b1d4e4 100644 --- a/drivers/tty/serial/sh-sci.c +++ b/drivers/tty/serial/sh-sci.c @@ -1557,6 +1557,9 @@ static void sci_request_dma(struct uart_port *port) dev_dbg(port->dev, "%s: port %d\n", __func__, port->line); + if (uart_console(port)) + return; /* Cannot use DMA on console */ + if (!port->dev->of_node) return; -- 2.7.4