atmel_serial: use existing console options only if BRG is running
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 <hskinnemoen@atmel.com>
Acked-by: Andrew Victor <linux@maxim.org.za>
Tested-by: Marc Pignat <marc.pignat@hevs.ch>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/drivers/serial/atmel_serial.c b/drivers/serial/atmel_serial.c
index 4d1ccc2..0b7b274 100644
--- a/drivers/serial/atmel_serial.c
+++ b/drivers/serial/atmel_serial.c
@@ -834,13 +834,13 @@
{
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 @@
* 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));
}