[U-Boot] [PATCH v2 02/22] serial/ns16550: wait for TEMT before initializing
Scott Wood
scottwood at freescale.com
Tue Oct 30 03:04:50 CET 2012
TEMT is set when the transmitter is totally empty and all output has
finished.
This prevents output problems (including a loss of synchronization
observed on p2020 that persisted for quite a while) if SPL has output
still on its way out.
Signed-off-by: Scott Wood <scottwood at freescale.com>
--
v2: fixed typo in subject, and explained what the bit does in the changelog
---
drivers/serial/ns16550.c | 3 +++
1 file changed, 3 insertions(+)
diff --git a/drivers/serial/ns16550.c b/drivers/serial/ns16550.c
index 9027781..bbd91ca 100644
--- a/drivers/serial/ns16550.c
+++ b/drivers/serial/ns16550.c
@@ -36,6 +36,9 @@
void NS16550_init(NS16550_t com_port, int baud_divisor)
{
+ while (!(serial_in(&com_port->lsr) & UART_LSR_TEMT))
+ ;
+
serial_out(CONFIG_SYS_NS16550_IER, &com_port->ier);
#if (defined(CONFIG_OMAP) && !defined(CONFIG_OMAP3_ZOOM2)) || \
defined(CONFIG_AM33XX)
--
1.7.9.5
More information about the U-Boot
mailing list