From f9262c12c0084ddba445a9a42e98994018e51400 Mon Sep 17 00:00:00 2001 From: Andi Kleen Date: Wed, 8 Mar 2006 17:57:25 -0800 Subject: [PATCH] i386: port ATI timer fix from x86_64 to i386 II ATI chipsets tend to generate double timer interrupts for the local APIC timer when both the 8254 and the IO-APIC timer pins are enabled. This is because they route it to both and the result is anded together and the CPU ends up processing it twice. This patch changes check_timer to disable the 8254 routing for interrupt 0. I think it would be safe on all chipsets actually (i tested it on a couple and it worked everywhere) and Windows seems to do it in a similar way, but to be conservative this patch only enables this mode on ATI (and adds options to enable/disable too) Ported over from a similar x86-64 change. I reused the ACPI earlyquirk infrastructure for the ATI bridge check, but tweaked it a bit to work even without ACPI. Inspired by a patch from Chuck Ebbert, but redone. Cc: Chuck Ebbert <76306.1226@compuserve.com> Cc: "Brown, Len" Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- arch/i386/kernel/acpi/Makefile | 2 +- arch/i386/kernel/acpi/boot.c | 3 --- arch/i386/kernel/acpi/earlyquirk.c | 8 ++++++++ 3 files changed, 9 insertions(+), 4 deletions(-) (limited to 'arch/i386/kernel/acpi') diff --git a/arch/i386/kernel/acpi/Makefile b/arch/i386/kernel/acpi/Makefile index d51c7313cae..7e9ac99354f 100644 --- a/arch/i386/kernel/acpi/Makefile +++ b/arch/i386/kernel/acpi/Makefile @@ -1,4 +1,4 @@ -obj-y := boot.o +obj-$(CONFIG_ACPI) += boot.o obj-$(CONFIG_X86_IO_APIC) += earlyquirk.o obj-$(CONFIG_ACPI_SLEEP) += sleep.o wakeup.o diff --git a/arch/i386/kernel/acpi/boot.c b/arch/i386/kernel/acpi/boot.c index 79577f0ace9..f1a21945963 100644 --- a/arch/i386/kernel/acpi/boot.c +++ b/arch/i386/kernel/acpi/boot.c @@ -1111,9 +1111,6 @@ int __init acpi_boot_table_init(void) disable_acpi(); return error; } -#ifdef __i386__ - check_acpi_pci(); -#endif acpi_table_parse(ACPI_BOOT, acpi_parse_sbf); diff --git a/arch/i386/kernel/acpi/earlyquirk.c b/arch/i386/kernel/acpi/earlyquirk.c index f1b9d2a46da..2e3b643a4dc 100644 --- a/arch/i386/kernel/acpi/earlyquirk.c +++ b/arch/i386/kernel/acpi/earlyquirk.c @@ -7,14 +7,22 @@ #include #include #include +#include static int __init check_bridge(int vendor, int device) { +#ifdef CONFIG_ACPI /* According to Nvidia all timer overrides are bogus. Just ignore them all. */ if (vendor == PCI_VENDOR_ID_NVIDIA) { acpi_skip_timer_override = 1; } +#endif + if (vendor == PCI_VENDOR_ID_ATI && timer_over_8254 == 1) { + timer_over_8254 = 0; + printk(KERN_INFO "ATI board detected. Disabling timer routing " + "over 8254.\n"); + } return 0; } -- cgit v1.2.3-70-g09d2