Commit-ID: 472a474c6630efd195d3738339fd1bdc8aa3b1aa Gitweb: http://git.kernel.org/tip/472a474c6630efd195d3738339fd1bdc8aa3b1aa Author: Suresh Siddha <suresh.b.siddha@xxxxxxxxx> AuthorDate: Wed, 31 Mar 2010 18:04:47 -0700 Committer: Ingo Molnar <mingo@xxxxxxx> CommitDate: Fri, 2 Apr 2010 20:48:47 +0200 x86: Fix double enable_IR_x2apic() call on SMP kernel on !SMP boards 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@xxxxxxxxxxx Signed-off-by: Suresh Siddha <suresh.b.siddha@xxxxxxxxx> Cc: <jbarnes@xxxxxxxxxxxxxxxx> Cc: <david.woodhouse@xxxxxxxxx> Cc: <weidong.han@xxxxxxxxx> Cc: <youquan.song@xxxxxxxxx> Cc: <Jan.Grossmann@xxxxxxxxxxx> Cc: <stable@xxxxxxxxxx> # [v2.6.32.x, v2.6.33.x] LKML-Reference: <1270083887.7835.78.camel@xxxxxxxxxxxxxxxxxxxx> Signed-off-by: Ingo Molnar <mingo@xxxxxxx> --- arch/x86/kernel/apic/apic.c | 2 ++ 1 files changed, 2 insertions(+), 0 deletions(-) diff --git a/arch/x86/kernel/apic/apic.c b/arch/x86/kernel/apic/apic.c index 00187f1..e5a4a1e 100644 --- a/arch/x86/kernel/apic/apic.c +++ b/arch/x86/kernel/apic/apic.c @@ -1640,8 +1640,10 @@ int __init APIC_init_uniprocessor(void) } #endif +#ifndef CONFIG_SMP enable_IR_x2apic(); default_setup_apic_routing(); +#endif verify_local_APIC(); connect_bsp_APIC(); -- To unsubscribe from this list: send the line "unsubscribe linux-tip-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html