summaryrefslogtreecommitdiffstats
path: root/drivers/tty/serial
diff options
context:
space:
mode:
authorGabriel Matni <gabriel.matni@exfo.com>2018-03-22 19:15:12 +0000
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2018-03-22 21:27:44 +0100
commitc685af1108d7c303f0b901413405d68eaeac4477 (patch)
treeea0d6e8358debb193b8eb233a0f019fe6ff152db /drivers/tty/serial
parent7693b331d033ecda61097007330d3e7461ff7f27 (diff)
downloadop-kernel-dev-c685af1108d7c303f0b901413405d68eaeac4477.zip
op-kernel-dev-c685af1108d7c303f0b901413405d68eaeac4477.tar.gz
serial: mvebu-uart: fix tx lost characters
Fixes missing characters on kernel console at low baud rates (i.e.9600). The driver should poll TX_RDY or TX_FIFO_EMP instead of TX_EMP to ensure that the transmitter holding register (THR) is ready to receive a new byte. TX_EMP tells us when it is possible to send a break sequence via SND_BRK_SEQ. While this also indicates that both the THR and the TSR are empty, it does not guarantee that a new byte can be written just yet. Fixes: 30530791a7a0 ("serial: mvebu-uart: initial support for Armada-3700 serial port") Reviewed-by: Miquel Raynal <miquel.raynal@bootlin.com> Acked-by: Gregory CLEMENT <gregory.clement@bootlin.com> Signed-off-by: Gabriel Matni <gabriel.matni@exfo.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/tty/serial')
-rw-r--r--drivers/tty/serial/mvebu-uart.c2
1 files changed, 1 insertions, 1 deletions
diff --git a/drivers/tty/serial/mvebu-uart.c b/drivers/tty/serial/mvebu-uart.c
index a4176af..750e564 100644
--- a/drivers/tty/serial/mvebu-uart.c
+++ b/drivers/tty/serial/mvebu-uart.c
@@ -618,7 +618,7 @@ static void wait_for_xmitr(struct uart_port *port)
u32 val;
readl_poll_timeout_atomic(port->membase + UART_STAT, val,
- (val & STAT_TX_EMP), 1, 10000);
+ (val & STAT_TX_RDY(port)), 1, 10000);
}
static void mvebu_uart_console_putchar(struct uart_port *port, int ch)
OpenPOWER on IntegriCloud