Re: State of LDP3430 platform

[Thomas Weber <thomas.weber.linux@googlemail.com>]

Am 16.01.2011 05:32, schrieb Paul Walmsley:
> On Sat, 15 Jan 2011, Russell King - ARM Linux wrote:
>
>> On Sat, Jan 15, 2011 at 12:38:46PM -0700, Paul Walmsley wrote:
>>> On Fri, 14 Jan 2011, Tony Lindgren wrote:
>>>
>>>> * Paul Walmsley <paul@pwsan.com> [101207 19:30]:
>>>>> On Tue, 7 Dec 2010, Paul Walmsley wrote:
>>>>>
>>>>> Regarding the watchdog problem, unfortunately, I can't reproduce on the 
>>>>> BeagleBoard with v2.6.37-rc5 with either omap2plus_defconfig or 
>>>>> omap2plus_defconfig without CONFIG_WATCHDOG.  If you send along your 
>>>>> .config, one of us can try to reproduce the problem with it.  Do the 
>>>>> 2.6.38 hwmod and wdt patchsets fix the problem for .38, at least?
>>>> I've been seeing this on my omap4 panda. While debugging it, I left
>>>> u-boot console only running for a few minutes to see if that stays up.
>>>> It did.. And after doing that somehow now my panda boots all the way
>>>> and stays up. Weird.
>>> Hmmm, do you think the watchdog is what's killing it?  I don't think 
>>> leaving u-boot running would affect that?
>> Right, well, the LDP3430 (and probably all OMAP) is broken by my
>> init_sched_clock() changes because I gave up with testing on OMAP
>> platforms.
>>
>> Why does OMAP initialize its clock sources soo late, outside of
>> the timer initialization?  This means you have no counter in place
>> (except for the jiffies counter) during early boot.
>>
>> Is there a reason why OMAP uniquely does this?
> I don't think so.
>
> Patch attached.
>
>
> - Paul
>
>
> [PATCH] OMAP: counter_32k: init clocksource as part of machine timer init
>
> Linus's master branch, currently at commit
> 1b59be2a6cdcb5a12e18d8315c07c94a624de48f ("Merge branch 'slab/urgent'
> of git://git.kernel.org/pub/scm/linux/kernel/git/penberg/slab-2.6"),
> crashes during boot on OMAP4430 ES2.0 Panda:
>
> [    0.000000] OMAP clockevent source: GPTIMER1 at 32768 Hz
> [    0.000000] Unable to handle kernel NULL pointer dereference at virtual address 00000000
> [    0.000000] pgd = c0004000
> [    0.000000] [00000000] *pgd=00000000
> [    0.000000] Internal error: Oops: 80000005 [#1] SMP
> [    0.000000] last sysfs file:
> [    0.000000] Modules linked in:
> [    0.000000] CPU: 0    Tainted: G        W    (2.6.37-07734-g2467802 #7)
> [    0.000000] PC is at 0x0
> [    0.000000] LR is at sched_clock_poll+0x2c/0x3c
> [    0.000000] pc : [<00000000>]    lr : [<c0060b74>]    psr: 600001d3
> [    0.000000] sp : c058bfd0  ip : c058a000  fp : 00000000
> [    0.000000] r10: 00000000  r9 : 411fc092  r8 : 800330c8
> [    0.000000] r7 : c05a08e0  r6 : c0034c48  r5 : c05ffc40  r4 : c0034c4c
> [    0.000000] r3 : c05ffe6c  r2 : c05a0bc0  r1 : c059f098  r0 : 00000000
> [    0.000000] Flags: nZCv  IRQs off  FIQs off  Mode SVC_32  ISA ARM  Segment kernel
> [    0.000000] Control: 10c53c7f  Table: 8000404a  DAC: 00000017
>
> This is due to the recent ARM init_sched_clock() changes and the late
> initialization of the counter_32k clock source:
>
>    http://marc.info/?l=linux-omap&m=129513468605208&w=2
>
> Fix by initializing the counter_32k clocksource during the machine timer
> initialization.
>
> Reported-by: Russell King <rmk+kernel@arm.linux.org.uk>
> Signed-off-by: Paul Walmsley <paul@pwsan.com>
>
> ---
>  arch/arm/mach-omap1/time.c               |    7 +++++++
>  arch/arm/mach-omap2/timer-gp.c           |   10 ++++++++--
>  arch/arm/plat-omap/counter_32k.c         |    3 +--
>  arch/arm/plat-omap/include/plat/common.h |    1 +
>  4 files changed, 17 insertions(+), 4 deletions(-)
>
> diff --git a/arch/arm/mach-omap1/time.c b/arch/arm/mach-omap1/time.c
> index ed7a61f..6ec65e5 100644
> --- a/arch/arm/mach-omap1/time.c
> +++ b/arch/arm/mach-omap1/time.c
> @@ -244,6 +244,13 @@ static void __init omap_timer_init(void)
>  
>  	omap_init_mpu_timer(rate);
>  	omap_init_clocksource(rate);
> +	/*
> +	 * XXX Since this file seems to deal mostly with the MPU timer,
> +	 * this doesn't seem like the correct place for the sync timer
> +	 * clocksource init.
> +	 */
> +	if (!cpu_is_omap7xx() && !cpu_is_omap15xx())
> +		omap_init_clocksource_32k();
>  }
>  
>  struct sys_timer omap_timer = {
> diff --git a/arch/arm/mach-omap2/timer-gp.c b/arch/arm/mach-omap2/timer-gp.c
> index 4e48e78..57d53e0 100644
> --- a/arch/arm/mach-omap2/timer-gp.c
> +++ b/arch/arm/mach-omap2/timer-gp.c
> @@ -42,6 +42,8 @@
>  
>  #include "timer-gp.h"
>  
> +#include <plat/common.h>
> +
>  /* MAX_GPTIMER_ID: number of GPTIMERs on the chip */
>  #define MAX_GPTIMER_ID		12
>  
> @@ -176,10 +178,14 @@ static void __init omap2_gp_clockevent_init(void)
>  /* 
>   * When 32k-timer is enabled, don't use GPTimer for clocksource
>   * instead, just leave default clocksource which uses the 32k
> - * sync counter.  See clocksource setup in see plat-omap/common.c. 
> + * sync counter.  See clocksource setup in plat-omap/timer-32k.c
>   */
>  
> -static inline void __init omap2_gp_clocksource_init(void) {}
> +static void __init omap2_gp_clocksource_init(void)
> +{
> +	omap_init_clocksource_32k();
> +}
> +
>  #else
>  /*
>   * clocksource
> diff --git a/arch/arm/plat-omap/counter_32k.c b/arch/arm/plat-omap/counter_32k.c
> index ea46440..0367998 100644
> --- a/arch/arm/plat-omap/counter_32k.c
> +++ b/arch/arm/plat-omap/counter_32k.c
> @@ -160,7 +160,7 @@ void read_persistent_clock(struct timespec *ts)
>  	*ts = *tsp;
>  }
>  
> -static int __init omap_init_clocksource_32k(void)
> +int __init omap_init_clocksource_32k(void)
>  {
>  	static char err[] __initdata = KERN_ERR
>  			"%s: can't register clocksource!\n";
> @@ -195,7 +195,6 @@ static int __init omap_init_clocksource_32k(void)
>  	}
>  	return 0;
>  }
> -arch_initcall(omap_init_clocksource_32k);
>  
>  #endif	/* !(defined(CONFIG_ARCH_OMAP730) || defined(CONFIG_ARCH_OMAP15XX)) */
>  
> diff --git a/arch/arm/plat-omap/include/plat/common.h b/arch/arm/plat-omap/include/plat/common.h
> index 6b8088e..84c707f 100644
> --- a/arch/arm/plat-omap/include/plat/common.h
> +++ b/arch/arm/plat-omap/include/plat/common.h
> @@ -35,6 +35,7 @@ struct sys_timer;
>  
>  extern void omap_map_common_io(void);
>  extern struct sys_timer omap_timer;
> +extern int __init omap_init_clocksource_32k(void);
>  
>  extern void omap_reserve(void);
>  

This patch works on Devkit8000. Thanks.

Tested-by: Thomas Weber <weber@corscience.de>