| From 472a474c6630efd195d3738339fd1bdc8aa3b1aa Mon Sep 17 00:00:00 2001 |
| From: Suresh Siddha <suresh.b.siddha@intel.com> |
| Date: Wed, 31 Mar 2010 18:04:47 -0700 |
| Subject: x86: Fix double enable_IR_x2apic() call on SMP kernel on !SMP boards |
| |
| From: Suresh Siddha <suresh.b.siddha@intel.com> |
| |
| commit 472a474c6630efd195d3738339fd1bdc8aa3b1aa upstream. |
| |
| Jan Grossmann reported kernel boot panic while booting SMP |
| kernel on his system with a single core cpu. SMP kernels call |
| enable_IR_x2apic() from native_smp_prepare_cpus() and on |
| platforms where the kernel doesn't find SMP configuration we |
| ended up again calling enable_IR_x2apic() from the |
| APIC_init_uniprocessor() call in the smp_sanity_check(). Thus |
| leading to kernel panic. |
| |
| Don't call enable_IR_x2apic() and default_setup_apic_routing() |
| from APIC_init_uniprocessor() in CONFIG_SMP case. |
| |
| NOTE: this kind of non-idempotent and assymetric initialization |
| sequence is rather fragile and unclean, we'll clean that up |
| in v2.6.35. This is the minimal fix for v2.6.34. |
| |
| Reported-by: Jan.Grossmann@kielnet.net |
| Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com> |
| Cc: <jbarnes@virtuousgeek.org> |
| Cc: <david.woodhouse@intel.com> |
| Cc: <weidong.han@intel.com> |
| Cc: <youquan.song@intel.com> |
| Cc: <Jan.Grossmann@kielnet.net> |
| LKML-Reference: <1270083887.7835.78.camel@sbs-t61.sc.intel.com> |
| Signed-off-by: Ingo Molnar <mingo@elte.hu> |
| Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de> |
| |
| --- |
| arch/x86/kernel/apic/apic.c | 2 ++ |
| 1 file changed, 2 insertions(+) |
| |
| --- a/arch/x86/kernel/apic/apic.c |
| +++ b/arch/x86/kernel/apic/apic.c |
| @@ -1664,8 +1664,10 @@ int __init APIC_init_uniprocessor(void) |
| } |
| #endif |
| |
| +#ifndef CONFIG_SMP |
| enable_IR_x2apic(); |
| default_setup_apic_routing(); |
| +#endif |
| |
| verify_local_APIC(); |
| connect_bsp_APIC(); |
