[PATCH 2/2] serial: lpuart: handle Overrun flag

[Sébastien Szymanski]

The receive FIFO may overflow if data are sent while U-Boot is still
booting. In that case, the Overrun flag (STAT[19]) is set and no
additional data is stored in the receive FIFO and the user cannot get
access to the U-Boot prompt.

Fix this by clearing the Overrun flag in _lpuart32_serial_tstc()

Signed-off-by: Sébastien Szymanski <sebastien.szymanski at armadeus.com>
---
 drivers/serial/serial_lpuart.c | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/drivers/serial/serial_lpuart.c b/drivers/serial/serial_lpuart.c
index bbce59443388..0728feccd131 100644
--- a/drivers/serial/serial_lpuart.c
+++ b/drivers/serial/serial_lpuart.c
@@ -367,10 +367,13 @@ static int _lpuart32_serial_putc(struct lpuart_serial_plat *plat,
 static int _lpuart32_serial_tstc(struct lpuart_serial_plat *plat)
 {
 	struct lpuart_fsl_reg32 *base = plat->reg;
-	u32 water;
+	u32 water, stat;
 
-	lpuart_read32(plat->flags, &base->water, &water);
+	lpuart_read32(plat->flags, &base->stat, &stat);
+	if (stat & STAT_OR)
+		lpuart_write32(plat->flags, &base->stat, STAT_OR);
 
+	lpuart_read32(plat->flags, &base->water, &water);
 	if ((water >> 24) == 0)
 		return 0;
 

-- 
2.52.0