[PATCH -tip] x86: ioapic -- don't call disconnect_bsp_APIC if noAPIC present

From: Cyrill Gorcunov
Date: Wed Jun 17 2009 - 14:13:35 EST


Vegard Nossum reported:

[ 503.576724] ACPI: Preparing to enter system sleep state S5
[ 503.710857] Disabling non-boot CPUs ...
[ 503.716853] Power down.
[ 503.717770] ------------[ cut here ]------------
[ 503.717770] WARNING: at arch/x86/kernel/apic/apic.c:249 native_apic_write_du)
[ 503.717770] Hardware name: OptiPlex GX100
[ 503.717770] Modules linked in:
[ 503.717770] Pid: 2136, comm: halt Not tainted 2.6.30 #443
[ 503.717770] Call Trace:
[ 503.717770] [<c154d327>] ? printk+0x18/0x1a
[ 503.717770] [<c1017358>] ? native_apic_write_dummy+0x38/0x50
[ 503.717770] [<c10360fc>] warn_slowpath_common+0x6c/0xc0
[ 503.717770] [<c1017358>] ? native_apic_write_dummy+0x38/0x50
[ 503.717770] [<c1036165>] warn_slowpath_null+0x15/0x20
[ 503.717770] [<c1017358>] native_apic_write_dummy+0x38/0x50
[ 503.717770] [<c1017173>] disconnect_bsp_APIC+0x63/0x100
[ 503.717770] [<c1019e48>] disable_IO_APIC+0xb8/0xc0
[ 503.717770] [<c1214231>] ? acpi_power_off+0x0/0x29
[ 503.717770] [<c1015e55>] native_machine_shutdown+0x65/0x80
[ 503.717770] [<c1015c36>] native_machine_power_off+0x26/0x30
[ 503.717770] [<c1015c49>] machine_power_off+0x9/0x10
[ 503.717770] [<c1046596>] kernel_power_off+0x36/0x40
[ 503.717770] [<c104680d>] sys_reboot+0xfd/0x1f0
[ 503.717770] [<c109daa0>] ? perf_swcounter_event+0xb0/0x130
[ 503.717770] [<c109db7d>] ? perf_counter_task_sched_out+0x5d/0x120
[ 503.717770] [<c102dfc6>] ? finish_task_switch+0x56/0xd0
[ 503.717770] [<c154da1e>] ? schedule+0x49e/0xb40
[ 503.717770] [<c10444b0>] ? sys_kill+0x70/0x160
[ 503.717770] [<c119d9db>] ? selinux_file_ioctl+0x3b/0x50
[ 503.717770] [<c10dd443>] ? sys_ioctl+0x63/0x70
[ 503.717770] [<c1003024>] sysenter_do_call+0x12/0x22
[ 503.717770] ---[ end trace 8157b5d0ed378f15 ]---

|
| That's including this commit:
|
| commit 103428e57be323c3c5545db8ad12667099bc6005
|Author: Cyrill Gorcunov <gorcunov@xxxxxxxxxx>
|Date: Sun Jun 7 16:48:40 2009 +0400
|
| x86, apic: Fix dummy apic read operation together with broken MP handling
|

If we have apic disabled we don't even switch to APIC mode and do not
calling for connect_bsp_APIC. Though on SMP compiled kernel the
native_machine_shutdown does try to write the apic register anyway.

Fix it with explicit check if we really should touch apic registers.

Reported-by: Vegard Nossum <vegard.nossum@xxxxxxxxx>
Signed-off-by: Cyrill Gorcunov <gorcunov@xxxxxxxxxx>
---
arch/x86/kernel/apic/io_apic.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)

Index: linux-2.6.git/arch/x86/kernel/apic/io_apic.c
=====================================================================
--- linux-2.6.git.orig/arch/x86/kernel/apic/io_apic.c
+++ linux-2.6.git/arch/x86/kernel/apic/io_apic.c
@@ -2003,7 +2003,9 @@ void disable_IO_APIC(void)
/*
* Use virtual wire A mode when interrupt remapping is enabled.
*/
- disconnect_bsp_APIC(!intr_remapping_enabled && ioapic_i8259.pin != -1);
+ if (cpu_has_apic)
+ disconnect_bsp_APIC(!intr_remapping_enabled &&
+ ioapic_i8259.pin != -1);
}

#ifdef CONFIG_X86_32
--
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