mirror of
https://github.com/brain-hackers/u-boot-brain
synced 2024-08-20 08:58:52 +09:00
![Wilson Lee](/assets/img/avatar_default.png)
In U-boot, serial_tstc was use to determine is there have a character in serial console that pending for read. If there is no "pending" function implemented in serial driver, the serial-uclass will return "true(1)" to indicate there have a character pending to read. Thus, read a character from nulldev serial will result in continuous getting -EAGAIN return which might lead system to hang. This commit is to fix a bug in nulldev serial which implement "pending" function in nulldev serial to always indicate there is no character in console that pending for read. Signed-off-by: Wilson Lee <wilson.lee@ni.com> Cc: Joe Hershberger <joe.hershberger@ni.com> Cc: Keng Soon Cheah <keng.soon.cheah@ni.com> Cc: Chen Yee Chew <chen.yee.chew@ni.com> Cc: Bin Meng <bmeng.cn@gmail.com>
55 lines
976 B
C
55 lines
976 B
C
/*
|
|
* Copyright (c) 2015 National Instruments
|
|
*
|
|
* SPDX-License-Identifier: GPL-2.0+
|
|
*/
|
|
|
|
#include <common.h>
|
|
#include <dm.h>
|
|
#include <serial.h>
|
|
|
|
static int nulldev_serial_setbrg(struct udevice *dev, int baudrate)
|
|
{
|
|
return 0;
|
|
}
|
|
|
|
static int nulldev_serial_getc(struct udevice *dev)
|
|
{
|
|
return -EAGAIN;
|
|
}
|
|
|
|
static int nulldev_serial_pending(struct udevice *dev, bool input)
|
|
{
|
|
return 0;
|
|
}
|
|
|
|
static int nulldev_serial_input(struct udevice *dev)
|
|
{
|
|
return 0;
|
|
}
|
|
|
|
static int nulldev_serial_putc(struct udevice *dev, const char ch)
|
|
{
|
|
return 0;
|
|
}
|
|
|
|
static const struct udevice_id nulldev_serial_ids[] = {
|
|
{ .compatible = "nulldev-serial" },
|
|
{ }
|
|
};
|
|
|
|
|
|
const struct dm_serial_ops nulldev_serial_ops = {
|
|
.putc = nulldev_serial_putc,
|
|
.pending = nulldev_serial_pending,
|
|
.getc = nulldev_serial_getc,
|
|
.setbrg = nulldev_serial_setbrg,
|
|
};
|
|
|
|
U_BOOT_DRIVER(serial_nulldev) = {
|
|
.name = "serial_nulldev",
|
|
.id = UCLASS_SERIAL,
|
|
.of_match = nulldev_serial_ids,
|
|
.ops = &nulldev_serial_ops,
|
|
};
|