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| author | Andi Kleen <ak@suse.de> | 2006-02-16 23:42:04 +0100 |
|---|---|---|
| committer | Linus Torvalds <torvalds@g5.osdl.org> | 2006-02-17 08:00:40 -0800 |
| commit | ab68805955ee3dd84a6aa76cd70e61fde996968d (patch) | |
| tree | abeaadcc28a6d60ca31fe85a732ace6a6df1232e /arch/x86_64 | |
| parent | 2391c4b594eb28abd58102de8f4e5d7a4fa39f4c (diff) | |
| download | talos-obmc-linux-ab68805955ee3dd84a6aa76cd70e61fde996968d.tar.gz talos-obmc-linux-ab68805955ee3dd84a6aa76cd70e61fde996968d.zip | |
[PATCH] x86_64: Don't enable ATI apicmaintimer workaround when the machine has C2 or C3
Many laptops have problems with ticking the local APIC timer in C2/C3.
The code added earlier to use it by default on ATI didn't really work
for them. Don't enable it when the system supports C2/C3.
This doesn't fix the problem fully, but at least it's not worse than before.
Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Diffstat (limited to 'arch/x86_64')
| -rw-r--r-- | arch/x86_64/kernel/io_apic.c | 16 |
1 files changed, 16 insertions, 0 deletions
diff --git a/arch/x86_64/kernel/io_apic.c b/arch/x86_64/kernel/io_apic.c index 4282d72b2a26..2585c1d92b26 100644 --- a/arch/x86_64/kernel/io_apic.c +++ b/arch/x86_64/kernel/io_apic.c @@ -30,6 +30,9 @@ #include <linux/mc146818rtc.h> #include <linux/acpi.h> #include <linux/sysdev.h> +#ifdef CONFIG_ACPI +#include <acpi/acpi_bus.h> +#endif #include <asm/io.h> #include <asm/smp.h> @@ -260,6 +263,8 @@ __setup("apic", enable_ioapic_setup); And another hack to disable the IOMMU on VIA chipsets. + ... and others. Really should move this somewhere else. + Kludge-O-Rama. */ void __init check_ioapic(void) { @@ -307,6 +312,17 @@ void __init check_ioapic(void) case PCI_VENDOR_ID_ATI: if (apic_runs_main_timer != 0) break; +#ifdef CONFIG_ACPI + /* Don't do this for laptops right + right now because their timer + doesn't necessarily tick in C2/3 */ + if (acpi_fadt.revision >= 3 && + (acpi_fadt.plvl2_lat + acpi_fadt.plvl3_lat) < 1100) { + printk(KERN_INFO +"ATI board detected, but seems to be a laptop. Timer might be shakey, sorry\n"); + break; + } +#endif printk(KERN_INFO "ATI board detected. Using APIC/PM timer.\n"); apic_runs_main_timer = 1; |
