Re: BUG lapic: Can't boot on battery (2.6.21-rc{1,2,3,4})

From: Thomas Gleixner
Date: Wed Mar 21 2007 - 08:08:43 EST


Stefan, Grzegorz

On Wed, 2007-03-21 at 12:14 +0100, Thomas Gleixner wrote:
> On Wed, 2007-03-21 at 11:37 +0100, Andi Kleen wrote:
> > > The BIOS/ACPI is broken and does only expose C1, which should not switch
> > > off LAPIC. The BIOS is switching into deeper C-States behind the kernels
> > > back somehow.
> >
> > Hmm, perhaps we can check AMD && (cstate >= 2 || has a battery) ?
> > Should be doable by looking up the battery object in ACPI
>
> Which makes us rely on another ACPI feature. What guarantees that the
> ACPI tables are correct for this one ?

Can you please apply the patch below and add "nolapic_timer" to the
kernel command line ?

Please provide also the output of

# dmidecode

on your laptops.

Thanks,

tglx

diff --git a/arch/i386/kernel/apic.c b/arch/i386/kernel/apic.c
index 5cff797..67f8d9f 100644
--- a/arch/i386/kernel/apic.c
+++ b/arch/i386/kernel/apic.c
@@ -61,6 +61,8 @@ static int enable_local_apic __initdata = 0;

/* Local APIC timer verification ok */
static int local_apic_timer_verify_ok;
+/* Disable local APIC timer from the kernel commandline */
+static int local_apic_timer_disabled;

/*
* Debug level, exported for io_apic.c
@@ -340,6 +342,13 @@ void __init setup_boot_APIC_clock(void)
long delta, deltapm;
int pm_referenced = 0;

+ if (local_apic_timer_disabled) {
+ /* No broadcast on UP ! */
+ if (num_possible_cpus() > 1)
+ setup_APIC_timer();
+ return;
+ }}
+
apic_printk(APIC_VERBOSE, "Using local APIC timer interrupts.\n"
"calibrating APIC timer ...\n");

@@ -1179,6 +1188,13 @@ static int __init parse_nolapic(char *arg)
}
early_param("nolapic", parse_nolapic);

+static int __init parse_disable_lapic_timer(char *arg)
+{
+ local_apic_timer_disabled = 1;
+ return 0;
+}
+early_param("nolapic_timer", parse_disable_lapic_timer);
+
static int __init apic_set_verbosity(char *str)
{
if (strcmp("debug", str) == 0)


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