Hi Daniel,
Some comments about the Adeos patch for the i.MX21/CSB535FS board. The inlined
patch
has been rebuilt by diff'ing the vanilla Adeos 1.2-00 support with yours.
> --- linux-2.6.14/arch/arm/kernel/ipipe-core.c 2006-04-21
16:17:02.000000000 +0200
> +++ linux-2.6.14-heig/arch/arm/kernel/ipipe-core.c 2006-04-21
15:33:47.000000000 +0200
> @@ -22,6 +22,12 @@
> * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
> *
> * Architecture-dependent I-PIPE core support for ARM.
> + *
> + * April 2006 :
> + * Adapted to ARM9 i.MX21/CSB535FS board with Xenomai by S.Gerber,
G.Boutillier and D.Rossier
> + * University of Applied Sciences Western Switzerland
> + * Reconfigurable & Embedded Digital Systems, REDS Institute
> + *
> */
>
> #include <linux/config.h>
> @@ -320,11 +326,19 @@ static void __ipipe_set_decr(void)
> int ipipe_tune_timer(unsigned long ns, int flags)
> {
> unsigned long x, ticks;
> + unsigned long us;
>
> if (flags & IPIPE_RESET_TIMER)
> ticks = __ipipe_mach_ticks_per_jiffy;
> else {
> - ticks = ns * __ipipe_mach_ticks_per_jiffy / (1000000000 / HZ);
> +
> + /*
> + * FIXME : Temporary convert ns to us. With nanosecondes we have a
problem
> + * with overflow.
> + * ticks = ns * __ipipe_mach_ticks_per_jiffy / (1000000000
/ HZ);
> + */
> + us = ns / 1000;
> + ticks = ((us * __ipipe_mach_ticks_per_jiffy) / 10000);
>
This change is going to be wrong when CONFIG_HZ != 1000,
this is why HZ should remain in the picture. This said, the original expression
looks
overly complicated, something like the following should do without risking the
overflow:
- ticks = ns * __ipipe_mach_ticks_per_jiffy / (1000000000 / HZ);
+ ticks = ns / (TICKS_PER_uSEC * 1000);
> if (ticks > __ipipe_mach_ticks_per_jiffy)
> return -EINVAL;
> diff -uNrp linux-2.6.14/arch/arm/kernel/process.c
linux-2.6.14-heig/arch/arm/kernel/process.c
> --- linux-2.6.14/arch/arm/kernel/process.c 2006-04-21 16:17:02.000000000 +0200
> +++ linux-2.6.14-heig/arch/arm/kernel/process.c 2006-04-21
15:33:47.000000000 +0200
> @@ -7,6 +7,12 @@
> * This program is free software; you can redistribute it and/or modify
> * it under the terms of the GNU General Public License version 2 as
> * published by the Free Software Foundation.
> + *
> + * April 2006 :
> + * Adapted to ARM9 i.MX21/CSB535FS board with Xenomai by S.Gerber,
G.Boutillier and D.Rossier
> + * University of Applied Sciences Western Switzerland
> + * Reconfigurable & Embedded Digital Systems, REDS Institute
> + *
> */
> #include <stdarg.h>
>
> @@ -111,7 +117,14 @@ void cpu_idle(void)
> preempt_disable();
> leds_event(led_idle_start);
> while (!need_resched())
> +/*
> + * Width idle -> latenca of interrupts
> + */
> +#ifndef CONFIG_IPIPE
> idle();
> +#else
> + ;
> +#endif
Ouch. It would be saner to implement the idle mode switch one could pass
as a boot argument to the kernel (e.g. arch/i386/kernel/process.c),
accepting "poll" or "default", instead of hard-wiring the poll mode.
> leds_event(led_idle_end);
> preempt_enable();
> schedule();
> diff -uNrp linux-2.6.14/init/Kconfig linux-2.6.14-heig/init/Kconfig
> --- linux-2.6.14/init/Kconfig 2006-04-21 16:17:02.000000000 +0200
> +++ linux-2.6.14-heig/init/Kconfig 2006-04-21 15:34:01.000000000 +0200
> @@ -502,3 +502,20 @@ config STOP_MACHINE
> help
> Need stop_machine() primitive.
> endmenu
> +
> +menu "Real-time sub-system"
> +
The Xenomai-related stuff does not belong to the Adeos patch.
--
Philippe.
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