* [PATCH] m68k: restore lost coldfire CLOCK_TICK_RATE
@ 2009-06-20 20:11 Philippe De Muyter
2009-06-22 3:18 ` [uClinux-dev] " Greg Ungerer
2009-08-12 6:42 ` Greg Ungerer
0 siblings, 2 replies; 7+ messages in thread
From: Philippe De Muyter @ 2009-06-20 20:11 UTC (permalink / raw)
To: linux-kernel, uclinux-dev
Hello list,
The good definition of CLOCK_TICK_RATE for coldfires has been lost in the
merge of m68k and m68knommu include files. Restore it. Culprit :
http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commitdiff;h=ebafc17468d58bd903c886175ca84a4edc69ae1d;hp=34055b806a6334624e7e8af6eefc3aee42372a85
Signed-off-by: Philippe De Muyter <phdm@macqel.be>
diff -r 8dcc271a81a8 arch/m68k/include/asm/timex.h
--- a/arch/m68k/include/asm/timex.h Thu Jun 18 14:07:46 2009 -0700
+++ b/arch/m68k/include/asm/timex.h Sat Jun 20 21:46:25 2009 +0200
@@ -3,10 +3,23 @@
*
* m68k architecture timex specifications
*/
-#ifndef _ASMm68k_TIMEX_H
-#define _ASMm68k_TIMEX_H
+#ifndef _ASMm68K_TIMEX_H
+#define _ASMm68K_TIMEX_H
+#ifdef CONFIG_COLDFIRE
+/*
+ * CLOCK_TICK_RATE should give the underlying frequency of the tick timer
+ * to make ntp work best. For Coldfires, that's the main clock.
+ */
+#include <asm/coldfire.h>
+#define CLOCK_TICK_RATE MCF_CLK
+#else
+/*
+ * This default CLOCK_TICK_RATE is probably wrong for many 68k boards
+ * Users of those boards will need to check and modify accordingly
+ */
#define CLOCK_TICK_RATE 1193180 /* Underlying HZ */
+#endif
typedef unsigned long cycles_t;
^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: [uClinux-dev] [PATCH] m68k: restore lost coldfire CLOCK_TICK_RATE
2009-06-20 20:11 [PATCH] m68k: restore lost coldfire CLOCK_TICK_RATE Philippe De Muyter
@ 2009-06-22 3:18 ` Greg Ungerer
2009-06-24 21:11 ` Philippe De Muyter
2009-08-12 6:42 ` Greg Ungerer
1 sibling, 1 reply; 7+ messages in thread
From: Greg Ungerer @ 2009-06-22 3:18 UTC (permalink / raw)
To: uClinux development list; +Cc: linux-kernel
HI Philippe,
Philippe De Muyter wrote:
> Hello list,
>
> The good definition of CLOCK_TICK_RATE for coldfires has been lost in the
> merge of m68k and m68knommu include files. Restore it. Culprit :
> http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commitdiff;h=ebafc17468d58bd903c886175ca84a4edc69ae1d;hp=34055b806a6334624e7e8af6eefc3aee42372a85
>
> Signed-off-by: Philippe De Muyter <phdm@macqel.be>
Is it needed?
What is broken with the existing value?
Regards
Greg
> diff -r 8dcc271a81a8 arch/m68k/include/asm/timex.h
> --- a/arch/m68k/include/asm/timex.h Thu Jun 18 14:07:46 2009 -0700
> +++ b/arch/m68k/include/asm/timex.h Sat Jun 20 21:46:25 2009 +0200
> @@ -3,10 +3,23 @@
> *
> * m68k architecture timex specifications
> */
> -#ifndef _ASMm68k_TIMEX_H
> -#define _ASMm68k_TIMEX_H
> +#ifndef _ASMm68K_TIMEX_H
> +#define _ASMm68K_TIMEX_H
>
> +#ifdef CONFIG_COLDFIRE
> +/*
> + * CLOCK_TICK_RATE should give the underlying frequency of the tick timer
> + * to make ntp work best. For Coldfires, that's the main clock.
> + */
> +#include <asm/coldfire.h>
> +#define CLOCK_TICK_RATE MCF_CLK
> +#else
> +/*
> + * This default CLOCK_TICK_RATE is probably wrong for many 68k boards
> + * Users of those boards will need to check and modify accordingly
> + */
> #define CLOCK_TICK_RATE 1193180 /* Underlying HZ */
> +#endif
>
> typedef unsigned long cycles_t;
>
> _______________________________________________
> uClinux-dev mailing list
> uClinux-dev@uclinux.org
> http://mailman.uclinux.org/mailman/listinfo/uclinux-dev
> This message was resent by uclinux-dev@uclinux.org
> To unsubscribe see:
> http://mailman.uclinux.org/mailman/options/uclinux-dev
>
--
------------------------------------------------------------------------
Greg Ungerer -- Principal Engineer EMAIL: gerg@snapgear.com
SnapGear Group, McAfee PHONE: +61 7 3435 2888
825 Stanley St, FAX: +61 7 3891 3630
Woolloongabba, QLD, 4102, Australia WEB: http://www.SnapGear.com
^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: [uClinux-dev] [PATCH] m68k: restore lost coldfire CLOCK_TICK_RATE
2009-06-22 3:18 ` [uClinux-dev] " Greg Ungerer
@ 2009-06-24 21:11 ` Philippe De Muyter
2009-06-25 0:33 ` Greg Ungerer
0 siblings, 1 reply; 7+ messages in thread
From: Philippe De Muyter @ 2009-06-24 21:11 UTC (permalink / raw)
To: uClinux development list; +Cc: linux-kernel
Hi Greg,
On Mon, Jun 22, 2009 at 01:18:55PM +1000, Greg Ungerer wrote:
> HI Philippe,
>
> Philippe De Muyter wrote:
>> Hello list,
>> The good definition of CLOCK_TICK_RATE for coldfires has been lost in the
>> merge of m68k and m68knommu include files. Restore it. Culprit :
>> http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commitdiff;h=ebafc17468d58bd903c886175ca84a4edc69ae1d;hp=34055b806a6334624e7e8af6eefc3aee42372a85
>> Signed-off-by: Philippe De Muyter <phdm@macqel.be>
>
> Is it needed?
> What is broken with the existing value?
I am no ntp expert, but IIRC kernel/time/ntp.c needs to know the remainder
of CLOCK_TICK_RATE / HZ to obtain a good stability of the time. That's
probably only needed when you have ntpd running.
Philippe
^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: [uClinux-dev] [PATCH] m68k: restore lost coldfire CLOCK_TICK_RATE
2009-06-24 21:11 ` Philippe De Muyter
@ 2009-06-25 0:33 ` Greg Ungerer
2009-06-25 11:30 ` Arnd Bergmann
0 siblings, 1 reply; 7+ messages in thread
From: Greg Ungerer @ 2009-06-25 0:33 UTC (permalink / raw)
To: uClinux development list; +Cc: linux-kernel
Hi Philippe,
Philippe De Muyter wrote:
> Hi Greg,
>
> On Mon, Jun 22, 2009 at 01:18:55PM +1000, Greg Ungerer wrote:
>> HI Philippe,
>>
>> Philippe De Muyter wrote:
>>> Hello list,
>>> The good definition of CLOCK_TICK_RATE for coldfires has been lost in the
>>> merge of m68k and m68knommu include files. Restore it. Culprit :
>>> http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commitdiff;h=ebafc17468d58bd903c886175ca84a4edc69ae1d;hp=34055b806a6334624e7e8af6eefc3aee42372a85
>>> Signed-off-by: Philippe De Muyter <phdm@macqel.be>
>> Is it needed?
>> What is broken with the existing value?
>
> I am no ntp expert, but IIRC kernel/time/ntp.c needs to know the remainder
> of CLOCK_TICK_RATE / HZ to obtain a good stability of the time. That's
> probably only needed when you have ntpd running.
I thought it did that based on gettimeofday()? And that ends up
going through the underlying timer code, which for both of
the ColdFire timer types doesn't use CLOCK_TICK_RATE. They directly
use the MCF_CLK definition.
Regards
Greg
------------------------------------------------------------------------
Greg Ungerer -- Principal Engineer EMAIL: gerg@snapgear.com
SnapGear Group, McAfee PHONE: +61 7 3435 2888
825 Stanley St, FAX: +61 7 3891 3630
Woolloongabba, QLD, 4102, Australia WEB: http://www.SnapGear.com
^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: [uClinux-dev] [PATCH] m68k: restore lost coldfire CLOCK_TICK_RATE
2009-06-25 0:33 ` Greg Ungerer
@ 2009-06-25 11:30 ` Arnd Bergmann
0 siblings, 0 replies; 7+ messages in thread
From: Arnd Bergmann @ 2009-06-25 11:30 UTC (permalink / raw)
To: Greg Ungerer; +Cc: uClinux development list, linux-kernel
On Thursday 25 June 2009, Greg Ungerer wrote:
> I thought it did that based on gettimeofday()? And that ends up
> going through the underlying timer code, which for both of
> the ColdFire timer types doesn't use CLOCK_TICK_RATE. They directly
> use the MCF_CLK definition.
The problem is the definition of TICK_NSEC, which is calculated from
CLOCK_TICK_RATE. If you use the i8253 PIT tick rate, this will be
slightly different from the regular TICK_NSEC value of (1000000000 / HZ).
Arnd <><
^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: [uClinux-dev] [PATCH] m68k: restore lost coldfire CLOCK_TICK_RATE
2009-06-20 20:11 [PATCH] m68k: restore lost coldfire CLOCK_TICK_RATE Philippe De Muyter
2009-06-22 3:18 ` [uClinux-dev] " Greg Ungerer
@ 2009-08-12 6:42 ` Greg Ungerer
2009-08-13 2:25 ` Philippe De Muyter
1 sibling, 1 reply; 7+ messages in thread
From: Greg Ungerer @ 2009-08-12 6:42 UTC (permalink / raw)
To: uClinux development list; +Cc: linux-kernel
Hi Philippe,
Philippe De Muyter wrote:
> The good definition of CLOCK_TICK_RATE for coldfires has been lost in the
> merge of m68k and m68knommu include files. Restore it. Culprit :
> http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commitdiff;h=ebafc17468d58bd903c886175ca84a4edc69ae1d;hp=34055b806a6334624e7e8af6eefc3aee42372a85
>
> Signed-off-by: Philippe De Muyter <phdm@macqel.be>
I have added this to the for-linus branch at
git://git.kernel.org/pub/scm/linux/kernel/git/gerg/m68knommu.git.
Thanks
Greg
> diff -r 8dcc271a81a8 arch/m68k/include/asm/timex.h
> --- a/arch/m68k/include/asm/timex.h Thu Jun 18 14:07:46 2009 -0700
> +++ b/arch/m68k/include/asm/timex.h Sat Jun 20 21:46:25 2009 +0200
> @@ -3,10 +3,23 @@
> *
> * m68k architecture timex specifications
> */
> -#ifndef _ASMm68k_TIMEX_H
> -#define _ASMm68k_TIMEX_H
> +#ifndef _ASMm68K_TIMEX_H
> +#define _ASMm68K_TIMEX_H
>
> +#ifdef CONFIG_COLDFIRE
> +/*
> + * CLOCK_TICK_RATE should give the underlying frequency of the tick timer
> + * to make ntp work best. For Coldfires, that's the main clock.
> + */
> +#include <asm/coldfire.h>
> +#define CLOCK_TICK_RATE MCF_CLK
> +#else
> +/*
> + * This default CLOCK_TICK_RATE is probably wrong for many 68k boards
> + * Users of those boards will need to check and modify accordingly
> + */
> #define CLOCK_TICK_RATE 1193180 /* Underlying HZ */
> +#endif
>
> typedef unsigned long cycles_t;
>
> _______________________________________________
> uClinux-dev mailing list
> uClinux-dev@uclinux.org
> http://mailman.uclinux.org/mailman/listinfo/uclinux-dev
> This message was resent by uclinux-dev@uclinux.org
> To unsubscribe see:
> http://mailman.uclinux.org/mailman/options/uclinux-dev
>
--
------------------------------------------------------------------------
Greg Ungerer -- Principal Engineer EMAIL: gerg@snapgear.com
SnapGear Group, McAfee PHONE: +61 7 3435 2888
825 Stanley St, FAX: +61 7 3891 3630
Woolloongabba, QLD, 4102, Australia WEB: http://www.SnapGear.com
^ permalink raw reply [flat|nested] 7+ messages in thread
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2009-06-20 20:11 [PATCH] m68k: restore lost coldfire CLOCK_TICK_RATE Philippe De Muyter
2009-06-22 3:18 ` [uClinux-dev] " Greg Ungerer
2009-06-24 21:11 ` Philippe De Muyter
2009-06-25 0:33 ` Greg Ungerer
2009-06-25 11:30 ` Arnd Bergmann
2009-08-12 6:42 ` Greg Ungerer
2009-08-13 2:25 ` Philippe De Muyter
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