From d8328f3b85f34c0dc5866f10bf6e7842fb511d62 Mon Sep 17 00:00:00 2001 From: Paul Walmsley Date: Sat, 15 Jan 2011 21:32:01 -0700 Subject: OMAP: counter_32k: init clocksource as part of machine timer init After commit dc548fbbd2ecd0fc3b02301d551e5f8e19ae58fd ("ARM: omap: convert sched_clock() to use new infrastructure"), OMAPs that use the 32KiHz "synchronization timer" as their clocksource crash during boot: [ 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 : [] 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. More information here: 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 Tested-by: Thomas Weber Signed-off-by: Paul Walmsley --- 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..7b7c268 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 + /* 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/counter_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); -- cgit v1.1