Re: 2.6.19 timer API changes

[Daniel Laird <danieljlaird@hotmail.com>]

Atsushi Nemoto wrote:
> 
> Hmm, do the TIMER1 and CP0_COUNTER run at same speed?  If no, the
> PNX8550 port should be broken (i.e. gettimeofday() did not work
> properly) even without the timer API changes.  You should provide
> custom clocksource.mips_read (previously named mips_hpt_read) function
> which returns TIMER1 counter value.  If the TIMER1 was not 32-bit
> free-run counter, some trick would be required.  Refer sb1250 or
> jmr3927 for example.
> 
> ---
> Atsushi Nemoto
> 
> 
> 
I am just starting to look into this (thankyou for your first comments).
I have reduced the problem code, so if I change the following:
/* For use both as a high precision timer and an interrupt source.  */
static void __init c0_hpt_timer_init(void)
{
	expirelo = read_c0_count() + cycles_per_jiffy;
	write_c0_compare(expirelo);
} (the 2.6.19 version)
to the following:
/* For use both as a high precision timer and an interrupt source.  */
static void __init c0_hpt_timer_init(void)
{
    unsigned int count = read_c0_count() - mips_hpt_read();
	expirelo = (count / cycles_per_jiffy + 1) * cycles_per_jiffy;
	write_c0_count(expirelo - cycles_per_jiffy);
	write_c0_compare(expirelo);
	write_c0_count(count);
}

Then i get the system to boot up and all seems well.  I am new to this and
am looking into why this change makes the system boot up.  As always though
any help is appreciated.

Cheers
Dan
-- 
View this message in context: http://www.nabble.com/2.6.19-timer-API-changes-tf2838715.html#a7948316
Sent from the linux-mips main mailing list archive at Nabble.com.