[coreboot] Patch set updated for coreboot: 453220d clear_ioapic: Fix reading of number of interrupts for IO-APICs

Aladyshev Konstantin (kostr@list.ru) gerrit at coreboot.org
Wed Dec 19 17:12:09 CET 2012

Aladyshev Konstantin (kostr at list.ru) just uploaded a new patch set to gerrit, which you can find at http://review.coreboot.org/2043


commit 453220d951b8482aa8274c6dcba1b6d165dad233
Author: Aladyshev Konstantin <aladyshev at nicevt.ru>
Date:   Tue Dec 18 22:29:20 2012 +0400

    clear_ioapic: Fix reading of number of interrupts for IO-APICs
    Apply the same fix for `setup_ioapic` as done in the following commit.
    commit 23c046b6f16805ff0131460189967bf261d704de Author: Nico Huber <nico.huber at secunet.com> Date: Mon Sep 24 10:48:43 2012 +0200
    	Fix reading of number of interrupts for IO-APICs
    	The number read from the io-apic register represents the index of the
    	highest interrupt redirection entry, i.e. the number of interrupts
    	minus one.
    	Change-Id: I54c992e4ff400de24bb9fef5d82251078f92c588
    	Signed-off-by: Nico Huber <nico.huber at secunet.com>
    	Reviewed-on: http://review.coreboot.org/1624
    	Tested-by: build bot (Jenkins)
    	Reviewed-by: Stefan Reinauer <stefan.reinauer at coreboot.org>
    Change-Id: I7b730d016a514c95c3b32aee6f31bd3d7b2c08cb
    Signed-off-by: Aladyshev Konstantin <aladyshev at nicevt.ru>
 src/arch/x86/lib/ioapic.c | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/src/arch/x86/lib/ioapic.c b/src/arch/x86/lib/ioapic.c
index 018a42c..e05d80c 100644
--- a/src/arch/x86/lib/ioapic.c
+++ b/src/arch/x86/lib/ioapic.c
@@ -43,8 +43,11 @@ void clear_ioapic(u32 ioapic_base)
 	/* Read the available number of interrupts. */
 	ioapic_interrupts = (io_apic_read(ioapic_base, 0x01) >> 16) & 0xff;
-	if (!ioapic_interrupts || ioapic_interrupts == 0xff)
-		ioapic_interrupts = 24;
+	if (ioapic_interrupts == 0xff)
+		ioapic_interrupts = 23;
+	ioapic_interrupts += 1; /* Bits 23-16 specify the maximum redirection
+				   entry, which is the number of interrupts
+				   minus 1. */
 	printk(BIOS_DEBUG, "IOAPIC: %d interrupts\n", ioapic_interrupts);
 	low = DISABLED;

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