From 3a5648259014abba09ea7f243b244b60660d4358 Mon Sep 17 00:00:00 2001 From: Eric Nelson Date: Wed, 14 May 2014 16:58:03 -0700 Subject: [PATCH] serial_mxc: disable new features of autobaud detection Bit 7 of UCR3 is described in the i.MX3x/i.MX5x/i.MX6x reference manuals as follows: Autobaud Detection Not Improved-. Disables new features of autobaud detection (See Baud Rate Automatic Detection Protocol, for more details). 0 Autobaud detection new features selected 1 Keep old autobaud detection mechanism On at least i.MX6DQ, i.MX6DLS and i.MX53, the "new features" occasionally cause the receiver to get out of sync and continuously produce received characters of '\xff'. This patch disables the "new feature" on all boards, since there's no support for auto-baud in U-Boot on any of them. More details are available in this post on i.MX Community: https://community.freescale.com/message/403254 Signed-off-by: Eric Nelson Tested-by: Fabio Estevam Acked-by: Stefano Babic --- drivers/serial/serial_mxc.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/serial/serial_mxc.c b/drivers/serial/serial_mxc.c index 56bee55208..313d560afc 100644 --- a/drivers/serial/serial_mxc.c +++ b/drivers/serial/serial_mxc.c @@ -77,7 +77,7 @@ #define UCR3_DSR (1<<10) /* Data set ready */ #define UCR3_DCD (1<<9) /* Data carrier detect */ #define UCR3_RI (1<<8) /* Ring indicator */ -#define UCR3_TIMEOUTEN (1<<7) /* Timeout interrupt enable */ +#define UCR3_ADNIMP (1<<7) /* Autobaud Detection Not Improved */ #define UCR3_RXDSEN (1<<6) /* Receive status interrupt enable */ #define UCR3_AIRINTEN (1<<5) /* Async IR wake interrupt enable */ #define UCR3_AWAKEN (1<<4) /* Async wake interrupt enable */ @@ -186,7 +186,7 @@ static int mxc_serial_init(void) while (!(__REG(UART_PHYS + UCR2) & UCR2_SRST)); - __REG(UART_PHYS + UCR3) = 0x0704; + __REG(UART_PHYS + UCR3) = 0x0704 | UCR3_ADNIMP; __REG(UART_PHYS + UCR4) = 0x8000; __REG(UART_PHYS + UESC) = 0x002b; __REG(UART_PHYS + UTIM) = 0x0; -- 2.25.1