From: Haavard Skinnemoen If BRGR is zero, the baud rate generator isn't running, so the boot loader can't have initialized the port. Signed-off-by: Haavard Skinnemoen Acked-by: Andrew Victor Tested-by: Marc Pignat Signed-off-by: Andrew Morton --- drivers/serial/atmel_serial.c | 15 +++++++-------- 1 file changed, 7 insertions(+), 8 deletions(-) diff -puN drivers/serial/atmel_serial.c~atmel_serial-use-existing-console-options-only-if-brg-is-running drivers/serial/atmel_serial.c --- a/drivers/serial/atmel_serial.c~atmel_serial-use-existing-console-options-only-if-brg-is-running +++ a/drivers/serial/atmel_serial.c @@ -834,13 +834,13 @@ static void __init atmel_console_get_opt { unsigned int mr, quot; -// TODO: CR is a write-only register -// unsigned int cr; -// -// cr = UART_GET_CR(port) & (ATMEL_US_RXEN | ATMEL_US_TXEN); -// if (cr == (ATMEL_US_RXEN | ATMEL_US_TXEN)) { -// /* ok, the port was enabled */ -// } + /* + * If the baud rate generator isn't running, the port wasn't + * initialized by the boot loader. + */ + quot = UART_GET_BRGR(port); + if (!quot) + return; mr = UART_GET_MR(port) & ATMEL_US_CHRL; if (mr == ATMEL_US_CHRL_8) @@ -860,7 +860,6 @@ static void __init atmel_console_get_opt * lower than one of those, as it would make us fall through * to a much lower baud rate than we really want. */ - quot = UART_GET_BRGR(port); *baud = port->uartclk / (16 * (quot - 1)); } _