From 2e0ad0e2c13534f1a0e7f63661e666c281e09b66 Mon Sep 17 00:00:00 2001 From: Jiang Liu Date: Mon, 9 Jun 2014 16:19:38 +0800 Subject: [PATCH] x86, ACPI, irq: Fix possible eror in GSI to IRQ mapping for legacy IRQ 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 Cc: Konrad Rzeszutek Wilk Cc: Tony Luck Cc: Joerg Roedel Cc: Paul Gortmaker Cc: Greg Kroah-Hartman Cc: Benjamin Herrenschmidt Cc: Grant Likely Cc: Rafael J. Wysocki Cc: Bjorn Helgaas Cc: Randy Dunlap Cc: Yinghai Lu Cc: Len Brown Cc: Pavel Machek Link: http://lkml.kernel.org/r/1402302011-23642-10-git-send-email-jiang.liu@linux.intel.com Signed-off-by: Thomas Gleixner --- 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 298f79616f1c..f3bafcd32b98 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; } -- 2.39.5