From: Sean Anderson <sean.anderson@seco.com>
To: linux-serial@vger.kernel.org,
Peter Korsgaard <peter.korsgaard@barco.com>,
Peter Korsgaard <peter@korsgaard.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
Shubhrajyoti Datta <shubhrajyoti.datta@xilinx.com>,
Michal Simek <michal.simek@xilinx.com>,
Sean Anderson <sean.anderson@seco.com>
Subject: [PATCH v2] tty: serial: uartlite: Use read_poll_timeout for a polling loop
Date: Thu, 26 Aug 2021 15:25:49 -0400 [thread overview]
Message-ID: <20210826192549.3203071-1-sean.anderson@seco.com> (raw)
read_poll_timeout was recently introduced, and can be used to simplify
our console polling loop. This results in a slight reduction in code.
early_uartlite_putc can't get the same treatment, because it can be
called before udelay is set up.
Signed-off-by: Sean Anderson <sean.anderson@seco.com>
---
Changes in v2:
- Elaborate commit message
drivers/tty/serial/uartlite.c | 18 +++++-------------
1 file changed, 5 insertions(+), 13 deletions(-)
diff --git a/drivers/tty/serial/uartlite.c b/drivers/tty/serial/uartlite.c
index f42ccc40ffa6..106bbbc86c87 100644
--- a/drivers/tty/serial/uartlite.c
+++ b/drivers/tty/serial/uartlite.c
@@ -17,6 +17,7 @@
#include <linux/interrupt.h>
#include <linux/init.h>
#include <linux/io.h>
+#include <linux/iopoll.h>
#include <linux/of.h>
#include <linux/of_address.h>
#include <linux/of_device.h>
@@ -448,24 +449,15 @@ static const struct uart_ops ulite_ops = {
static void ulite_console_wait_tx(struct uart_port *port)
{
u8 val;
- unsigned long timeout;
/*
* Spin waiting for TX fifo to have space available.
* When using the Microblaze Debug Module this can take up to 1s
*/
- timeout = jiffies + msecs_to_jiffies(1000);
- while (1) {
- val = uart_in32(ULITE_STATUS, port);
- if ((val & ULITE_STATUS_TXFULL) == 0)
- break;
- if (time_after(jiffies, timeout)) {
- dev_warn(port->dev,
- "timeout waiting for TX buffer empty\n");
- break;
- }
- cpu_relax();
- }
+ if (read_poll_timeout_atomic(uart_in32, val, !(val & ULITE_STATUS_TXFULL),
+ 0, 1000000, false, ULITE_STATUS, port))
+ dev_warn(port->dev,
+ "timeout waiting for TX buffer empty\n");
}
static void ulite_console_putchar(struct uart_port *port, int ch)
--
2.25.1
reply other threads:[~2021-08-26 19:26 UTC|newest]
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