Use cpu_relax() instead of barrier() in a tight polling loops to make
them a bit more idiomatic. Should also improve things on ARM64 a bit
since cpu_relax() will expand into "yield" instruction there.
Signed-off-by: Andrey Smirnov <andrew.smirnov@xxxxxxxxx>
Cc: Stefan Agner <stefan@xxxxxxxx>
Cc: Chris Healy <cphealy@xxxxxxxxx>
Cc: Cory Tusar <cory.tusar@xxxxxxxx>
Cc: Lucas Stach <l.stach@xxxxxxxxxxxxxx>
Cc: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
Cc: Jiri Slaby <jslaby@xxxxxxxx>
Cc: linux-imx@xxxxxxx
Cc: linux-serial@xxxxxxxxxxxxxxx
Cc: linux-kernel@xxxxxxxxxxxxxxx
---
drivers/tty/serial/fsl_lpuart.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/drivers/tty/serial/fsl_lpuart.c b/drivers/tty/serial/fsl_lpuart.c
index eb748ef85da7..58043e01a242 100644
--- a/drivers/tty/serial/fsl_lpuart.c
+++ b/drivers/tty/serial/fsl_lpuart.c
@@ -553,14 +553,14 @@ static void lpuart_wait_bit_set(struct uart_port *port, unsigned int offset,
u8 bit)
{
while (!(readb(port->membase + offset) & bit))
- barrier();
+ cpu_relax();
}
static void lpuart32_wait_bit_set(struct uart_port *port, unsigned int offset,
u32 bit)
{
while (!(lpuart32_read(port, offset) & bit))
- barrier();
+ cpu_relax();
}
#if defined(CONFIG_CONSOLE_POLL)
--
2.21.0
