From: Shardar Shariff Md <smohammed@xxxxxxxxxx>
FIFO reset/flush code implemented now does not follow programming
guidelines. RTS line has to be turned off while flushing FIFOs to
avoid new transfers. Also check LSR bits UART_LSR_TEMT and UART_LSR_DR
to confirm FIFOs are flushed.
Signed-off-by: Shardar Shariff Md <smohammed@xxxxxxxxxx>
Signed-off-by: Krishna Yarlagadda <kyarlagadda@xxxxxxxxxx>
---
drivers/tty/serial/serial-tegra.c | 14 ++++++++++++++
1 file changed, 14 insertions(+)
diff --git a/drivers/tty/serial/serial-tegra.c b/drivers/tty/serial/serial-tegra.c
index 29bf7b7..4cd6d5f 100644
--- a/drivers/tty/serial/serial-tegra.c
+++ b/drivers/tty/serial/serial-tegra.c
@@ -266,6 +266,10 @@ static void tegra_uart_wait_sym_time(struct tegra_uart_port *tup,
static void tegra_uart_fifo_reset(struct tegra_uart_port *tup, u8 fcr_bits)
{
unsigned long fcr = tup->fcr_shadow;
+ unsigned int lsr, tmout = 10000;
+
+ if (tup->rts_active)
+ set_rts(tup, false);
if (tup->cdata->allow_txfifo_reset_fifo_mode) {
fcr |= fcr_bits & (UART_FCR_CLEAR_RCVR | UART_FCR_CLEAR_XMIT);
@@ -289,6 +293,16 @@ static void tegra_uart_fifo_reset(struct tegra_uart_port *tup, u8 fcr_bits)
* to propagate, otherwise data could be lost.
*/
tegra_uart_wait_cycle_time(tup, 32);
+
+ do {
+ lsr = tegra_uart_read(tup, UART_LSR);
+ if ((lsr | UART_LSR_TEMT) && !(lsr & UART_LSR_DR))
+ break;
+ udelay(1);
+ } while (--tmout);
+
+ if (tup->rts_active)
+ set_rts(tup, true);
}
static int tegra_set_baudrate(struct tegra_uart_port *tup, unsigned int baud)
--
2.7.4
