[U-Boot-Users] [PATCH] MIPS time.c fix

[U-Boot-Users] [PATCH] MIPS time.c fix

[Robert Deliën]

Hi,

The patch attached makes the MIPS timer function get_timer return time in
CFG_HZ ticks, where CFG_HZ is set to 1000 per default.

The functions get_ticks and get_tbclk still work using the actual number of
COUNT register increments per second, which is equal to the cpu clock
frequency for MIPS processors.

With kind regards,

	Robert.

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[U-Boot-Users] [PATCH] MIPS time.c fix

[Andrew Dyer]

On 12/8/06, Robert Deli?n <robert.delien@nxp.com> wrote:
> Hi,
>
> The patch attached makes the MIPS timer function get_timer return time in
> CFG_HZ ticks, where CFG_HZ is set to 1000 per default.
>
> The functions get_ticks and get_tbclk still work using the actual number of
> COUNT register increments per second, which is equal to the cpu clock
> frequency for MIPS processors.

The above is not true for all MIPS.  A lot (almost all) of older MIPS
parts run the cpu CP0 counter at half the core clock rate.

I would suggest changing CPU_CLOCK_RATE to CPU_CP0_COUNT_RATE since
they are not always the same.

-- 
Hardware, n.:
        The parts of a computer system that can be kicked.

[U-Boot-Users] [PATCH] MIPS time.c fix

[Robert Deliën]

> The above is not true for all MIPS.  A lot (almost all) of older MIPS
> parts run the cpu CP0 counter at half the core clock rate.

Thanks for your feedback; I wasn't aware of this. I've encountered a couple
of /2 constructions in some configurations, but I though that was just a
quick fix that degrades the granularity of the timer by half in order to
prevent overflows in net.c.

> I would suggest changing CPU_CLOCK_RATE to CPU_CP0_COUNT_RATE since
> they are not always the same.

I have changed it to CFG_CP0_COUNT_RATE, if you don't mind. The IncaIP and
Purple platform seem to have cores with half-speed COUNT registers so those
have been fixed too. Behold the new patch ;-)

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