| From | Jiang Liu <> | Subject | [Patch V4 09/42] x86, ACPI, irq: fix possible eror in GSI to IRQ mapping for legacy IRQ | Date | Mon, 9 Jun 2014 16:19:38 +0800 |
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A default identity mapping between GSI and IRQ is built for legacy IRQs. So when overriding the default identity mapping for legacy IRQs, we should also invalidate isa_irq_to_gsi[gsi] when setting isa_irq_to_gsi[irq] = gsi. Otherwise there may be two entries with the same GSI in the isa_irq_to_gsi array, and acpi_isa_irq_to_gsi() may give wrong result.
Signed-off-by: Jiang Liu <jiang.liu@linux.intel.com> --- arch/x86/kernel/acpi/boot.c | 10 +++++++++- 1 file changed, 9 insertions(+), 1 deletion(-)
diff --git a/arch/x86/kernel/acpi/boot.c b/arch/x86/kernel/acpi/boot.c index f201579cd0df..d6493863bd4b 100644 --- a/arch/x86/kernel/acpi/boot.c +++ b/arch/x86/kernel/acpi/boot.c @@ -366,6 +366,13 @@ static void __init mp_override_legacy_irq(u8 bus_irq, u8 polarity, u8 trigger, mp_save_irq(&mp_irq); + /* + * Reset default identity mapping if gsi is also an legacy IRQ, + * otherwise there will be more than one entry with the same GSI + * and acpi_isa_irq_to_gsi() may give wrong result. + */ + if (gsi < NR_IRQS_LEGACY && isa_irq_to_gsi[gsi] == gsi) + isa_irq_to_gsi[gsi] = ACPI_INVALID_GSI; isa_irq_to_gsi[bus_irq] = gsi; } @@ -621,7 +628,8 @@ EXPORT_SYMBOL_GPL(acpi_gsi_to_irq); int acpi_isa_irq_to_gsi(unsigned isa_irq, u32 *gsi) { - if (isa_irq < NR_IRQS_LEGACY) { + if (isa_irq < NR_IRQS_LEGACY && + isa_irq_to_gsi[isa_irq] != ACPI_INVALID_GSI) { *gsi = isa_irq_to_gsi[isa_irq]; return 0; } -- 1.7.10.4
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