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 +++++++ 1 file changed, 7 insertions(+) (limited to 'arch/arm/mach-omap1') diff --git a/arch/arm/mach-omap1/time.c b/arch/arm/mach-omap1/time.c index ed7a61ff916a..6ec65e599997 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 = { -- cgit v1.2.3