Messages in this thread Patch in this message | | | Date | Mon, 6 Oct 2008 17:37:18 -0700 | From | Greg KH <> | Subject | [patch 01/71] x86-32: AMD c1e force timer broadcast late |
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2.6.26-stable review patch. If anyone has any objections, please let us know.
------------------ From: Chuck Ebbert <cebbert@redhat.com>
This patch is not needed in 2.6.27 because it has new c1e-aware idle code.
In kernel 2.6.26 the 32-bit x86 timers are started earlier than before. This breaks AMD c1e detection trying to force timer broadcast for the local apic timer. Copy the code from the 64-bit kernel to force timer broadcast late.
Reference: http://bugzilla.kernel.org/show_bug.cgi?id=11427
Signed-off-by: Chuck Ebbert <cebbert@redhat.com> Acked-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
--- arch/x86/kernel/apic_32.c | 25 ++++++++++++++++++++++++- 1 file changed, 24 insertions(+), 1 deletion(-)
--- a/arch/x86/kernel/apic_32.c +++ b/arch/x86/kernel/apic_32.c @@ -552,8 +552,31 @@ void __init setup_boot_APIC_clock(void) setup_APIC_timer(); } -void __devinit setup_secondary_APIC_clock(void) +/* + * AMD C1E enabled CPUs have a real nasty problem: Some BIOSes set the + * C1E flag only in the secondary CPU, so when we detect the wreckage + * we already have enabled the boot CPU local apic timer. Check, if + * disable_apic_timer is set and the DUMMY flag is cleared. If yes, + * set the DUMMY flag again and force the broadcast mode in the + * clockevents layer. + */ +static void __cpuinit check_boot_apic_timer_broadcast(void) +{ + if (!local_apic_timer_disabled || + (lapic_clockevent.features & CLOCK_EVT_FEAT_DUMMY)) + return; + + lapic_clockevent.features |= CLOCK_EVT_FEAT_DUMMY; + + local_irq_enable(); + clockevents_notify(CLOCK_EVT_NOTIFY_BROADCAST_FORCE, + &boot_cpu_physical_apicid); + local_irq_disable(); +} + +void __cpuinit setup_secondary_APIC_clock(void) { + check_boot_apic_timer_broadcast(); setup_APIC_timer(); } --
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