u-boot/lib/time.c
Stephen Warren 2cd1b57220 time: fix usec_to_tick()
Commit 8dfafdde88 ("Introduce common timer functions") created a
common definition of usec_to_tick() which had a couple problems:

static unsigned long long usec_to_tick(unsigned long usec)
{
       uint64_t tick = usec * get_tbclk();

That likely overflows.

       usec *= get_tbclk();

That was an attempt to fix it by performing the multiply after the
promotion of usec to 64-bit, but was applied to the wrong variable,
which was never used.

This patch fixes these issues. A user-visible symptom of the problem was
the e.g. "dhcp zImage" using an ASIX USB Ethernet dongle would print:

Waiting for Ethernet connection... unable to connect.

... with no delay before "unable to connect". There are likely other
symptoms.

Signed-off-by: Stephen Warren <swarren@nvidia.com>
Acked-by: Rob Herring <rob.herring@calxeda.com>
2013-12-13 09:15:33 -05:00

111 lines
2.1 KiB
C

/*
* (C) Copyright 2000-2009
* Wolfgang Denk, DENX Software Engineering, wd@denx.de.
*
* SPDX-License-Identifier: GPL-2.0+
*/
#include <common.h>
#include <watchdog.h>
#include <div64.h>
#include <asm/io.h>
#if CONFIG_SYS_HZ != 1000
#warning "CONFIG_SYS_HZ must be 1000 and should not be defined by platforms"
#endif
#ifndef CONFIG_WD_PERIOD
# define CONFIG_WD_PERIOD (10 * 1000 * 1000) /* 10 seconds default*/
#endif
DECLARE_GLOBAL_DATA_PTR;
#ifdef CONFIG_SYS_TIMER_RATE
ulong notrace get_tbclk(void)
{
return CONFIG_SYS_TIMER_RATE;
}
#endif
#ifdef CONFIG_SYS_TIMER_COUNTER
unsigned long notrace timer_read_counter(void)
{
#ifdef CONFIG_SYS_TIMER_COUNTS_DOWN
return ~readl(CONFIG_SYS_TIMER_COUNTER);
#else
return readl(CONFIG_SYS_TIMER_COUNTER);
#endif
}
#else
extern unsigned long __weak timer_read_counter(void);
#endif
unsigned long long __weak notrace get_ticks(void)
{
unsigned long now = timer_read_counter();
/* increment tbu if tbl has rolled over */
if (now < gd->timebase_l)
gd->timebase_h++;
gd->timebase_l = now;
return ((unsigned long long)gd->timebase_h << 32) | gd->timebase_l;
}
static unsigned long long notrace tick_to_time(uint64_t tick)
{
unsigned int div = get_tbclk();
tick *= CONFIG_SYS_HZ;
do_div(tick, div);
return tick;
}
ulong __weak get_timer(ulong base)
{
return tick_to_time(get_ticks()) - base;
}
unsigned long __weak notrace timer_get_us(void)
{
return tick_to_time(get_ticks() * 1000);
}
static unsigned long long usec_to_tick(unsigned long usec)
{
uint64_t tick = usec;
tick *= get_tbclk();
do_div(tick, 1000000);
return tick;
}
void __weak __udelay(unsigned long usec)
{
unsigned long long tmp;
ulong tmo;
tmo = usec_to_tick(usec);
tmp = get_ticks() + tmo; /* get current timestamp */
while (get_ticks() < tmp) /* loop till event */
/*NOP*/;
}
/* ------------------------------------------------------------------------- */
void udelay(unsigned long usec)
{
ulong kv;
do {
WATCHDOG_RESET();
kv = usec > CONFIG_WD_PERIOD ? CONFIG_WD_PERIOD : usec;
__udelay (kv);
usec -= kv;
} while(usec);
}
void mdelay(unsigned long msec)
{
while (msec--)
udelay(1000);
}