Jens Scharsig wrote:
> * Fix: return value of get_tbclk
> * this fixes issue with prematurely restart/retry, if BOOT_RETRY_TIMEOUT is
> used
>
>
> Signed-off-by: Jens Scharsig <js_at...@scharsoft.de>
> ---
> the V3 supports the actually file structure.
> the original patch
> http://lists.denx.de/pipermail/u-boot/2010-April/069415.html
> use the old directory /cpu/arch structure.
>
> arch/arm/cpu/arm926ejs/at91/timer.c | 5 +----
> 1 files changed, 1 insertions(+), 4 deletions(-)
>
> diff --git a/arch/arm/cpu/arm926ejs/at91/timer.c
> b/arch/arm/cpu/arm926ejs/at91/timer.c
> index d21eebf..8efc34b 100644
> --- a/arch/arm/cpu/arm926ejs/at91/timer.c
> +++ b/arch/arm/cpu/arm926ejs/at91/timer.c
> @@ -138,8 +138,5 @@ ulong get_timer(ulong base)
> */
> ulong get_tbclk(void)
> {
> - ulong tbclk;
> -
> - tbclk = CONFIG_SYS_HZ;
> - return tbclk;
> + return timer_freq;
> }
>
Dear Jens,
I think the timer.c is more broken that just that return value:
example 1:
/*
* timer without interrupts
*/
unsigned long long get_ticks(void)
{
at91_pit_t *pit = (at91_pit_t *) AT91_PIT_BASE;
ulong now = readl(&pit->piir);
if (now >= lastinc) /* normal mode (non roll) */
/* move stamp forward with absolut diff ticks */
timestamp += (now - lastinc);
else /* we have rollover of incrementer */
timestamp += (0xFFFFFFFF - lastinc) + now;
lastinc = now;
return timestamp;
}
observation: timestamp, lastinc, now are all ulong.
timestamp += (0xFFFFFFFF - lastinc) + now;
is the same as
timestamp += (now - lastinc) - 1;
so in case of a "rollover" timestamp is incremented just by one less.
I think the if is superfluous. ulong will handle the rollover automatically
example 2:
void __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*/;
}
observation: tmp being unsigned long long, get_ticks returning
the unsigned long timestamp, tmp being a sum of two ulongs,
the while might NEVER end. In practice that is very unlikely,
however the code should be corrected.
I was going to rework that timer sooner or later to address all
those issues, but you are welcome to go ahead, too. Just we
should avoid double work :)
Greetings, Reinhard
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