It may happen that the MXC serial IP block is performing some ongoing
transmission (started at e.g. board_init()) when the "initr_serial" is
called.
As a result the serial port IP block is reset, so transmitted data is
corrupted:
I2C: ready
DRAM: 1 GiB
jSS('HH��SL_SDHC: 04 rev 0x0
This patch prevents from this situation, by waiting for transmission
complete bit set (UART Status Register 2 (UARTx_USR2), bit TXDC):
I2C: ready
DRAM: 1 GiB
ID: unit type 0x4 rev 0x0
Signed-off-by: Lukasz Majewski <lu...@denx.de>
---
drivers/serial/serial_mxc.c | 7 +++++++
1 file changed, 7 insertions(+)
diff --git a/drivers/serial/serial_mxc.c b/drivers/serial/serial_mxc.c
index cce80a8..ef4eb12 100644
--- a/drivers/serial/serial_mxc.c
+++ b/drivers/serial/serial_mxc.c
@@ -141,6 +141,13 @@ struct mxc_uart {
static void _mxc_serial_init(struct mxc_uart *base)
{
+ /*
+ * Wait for any ongoing transmission to finish - for example
+ * from pre-relocation enabled UART
+ */
+ while (!(readl(&base->sr2) & USR2_TXDC))
+ ;
+
writel(0, &base->cr1);
writel(0, &base->cr2);
--
2.1.4
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