* [PATCH] serial: mvebu-uart: fix driver's tx_empty callback
@ 2021-09-11 13:20 Pali Rohár
0 siblings, 0 replies; only message in thread
From: Pali Rohár @ 2021-09-11 13:20 UTC (permalink / raw)
To: Greg Kroah-Hartman, Jiri Slaby
Cc: Russell King, Andrew Lunn, Marek Behún, linux-serial, linux-kernel
Driver's tx_empty callback should signal when the transmit shift register
is empty. So when the last character has been sent.
STAT_TX_FIFO_EMP bit signals only that HW transmit FIFO is empty, which
happens when the last byte is loaded into transmit shift register.
STAT_TX_EMP bit signals when the both HW transmit FIFO and transmit shift
register are empty.
So replace STAT_TX_FIFO_EMP check by STAT_TX_EMP in mvebu_uart_tx_empty()
callback function.
Signed-off-by: Pali Rohár <pali@kernel.org>
Fixes: 30530791a7a0 ("serial: mvebu-uart: initial support for Armada-3700 serial port")
---
drivers/tty/serial/mvebu-uart.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/tty/serial/mvebu-uart.c b/drivers/tty/serial/mvebu-uart.c
index 590f58176dc3..56ba7180f66d 100644
--- a/drivers/tty/serial/mvebu-uart.c
+++ b/drivers/tty/serial/mvebu-uart.c
@@ -191,7 +191,7 @@ static unsigned int mvebu_uart_tx_empty(struct uart_port *port)
st = readl(port->membase + UART_STAT);
spin_unlock_irqrestore(&port->lock, flags);
- return (st & STAT_TX_FIFO_EMP) ? TIOCSER_TEMT : 0;
+ return (st & STAT_TX_EMP) ? TIOCSER_TEMT : 0;
}
static unsigned int mvebu_uart_get_mctrl(struct uart_port *port)
--
2.20.1
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