[PATCH] i386: Handle non existing APICs without panicing
[description from AK]
This fixes booting in APIC mode on some ACER laptops. x86-64
did a similar change some time ago.
See http://bugzilla.kernel.org/show_bug.cgi?id=4700 for details
Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/arch/i386/kernel/io_apic.c b/arch/i386/kernel/io_apic.c
index f2dd218..235822b 100644
--- a/arch/i386/kernel/io_apic.c
+++ b/arch/i386/kernel/io_apic.c
@@ -2566,8 +2566,10 @@
spin_unlock_irqrestore(&ioapic_lock, flags);
/* Sanity check */
- if (reg_00.bits.ID != apic_id)
- panic("IOAPIC[%d]: Unable change apic_id!\n", ioapic);
+ if (reg_00.bits.ID != apic_id) {
+ printk("IOAPIC[%d]: Unable to change apic_id!\n", ioapic);
+ return -1;
+ }
}
apic_printk(APIC_VERBOSE, KERN_INFO
diff --git a/arch/i386/kernel/mpparse.c b/arch/i386/kernel/mpparse.c
index e7609ab..e6e2f43 100644
--- a/arch/i386/kernel/mpparse.c
+++ b/arch/i386/kernel/mpparse.c
@@ -915,6 +915,7 @@
u32 gsi_base)
{
int idx = 0;
+ int tmpid;
if (nr_ioapics >= MAX_IO_APICS) {
printk(KERN_ERR "ERROR: Max # of I/O APICs (%d) exceeded "
@@ -935,9 +936,14 @@
set_fixmap_nocache(FIX_IO_APIC_BASE_0 + idx, address);
if ((boot_cpu_data.x86_vendor == X86_VENDOR_INTEL) && (boot_cpu_data.x86 < 15))
- mp_ioapics[idx].mpc_apicid = io_apic_get_unique_id(idx, id);
+ tmpid = io_apic_get_unique_id(idx, id);
else
- mp_ioapics[idx].mpc_apicid = id;
+ tmpid = id;
+ if (tmpid == -1) {
+ nr_ioapics--;
+ return;
+ }
+ mp_ioapics[idx].mpc_apicid = tmpid;
mp_ioapics[idx].mpc_apicver = io_apic_get_version(idx);
/*