From ca64c47cecd0321b2e0dcbd7aaff44b68ce20654 Mon Sep 17 00:00:00 2001 From: "Maciej W. Rozycki" Date: Tue, 1 Dec 2009 15:31:15 -0800 Subject: [PATCH] x86, io-apic: Move the effort of clearing remoteIRR explicitly before migrating the irq When the level-triggered interrupt is seen as an edge interrupt, we try to clear the remoteIRR explicitly (using either an io-apic eoi register when present or through the idea of changing trigger mode of the io-apic RTE to edge and then back to level). But this explicit try also needs to happen before we try to migrate the irq. Otherwise irq migration attempt will fail anyhow, as it postpones the irq migration to a later attempt when it sees the remoteIRR in the io-apic RTE still set. Signed-off-by: "Maciej W. Rozycki" Reviewed-by: Suresh Siddha Cc: ebiederm@xmission.com Cc: garyhade@us.ibm.com LKML-Reference: <20091201233334.975416130@sbs-t61.sc.intel.com> Signed-off-by: Ingo Molnar --- arch/x86/kernel/apic/io_apic.c | 28 ++++++++++++++-------------- 1 file changed, 14 insertions(+), 14 deletions(-) diff --git a/arch/x86/kernel/apic/io_apic.c b/arch/x86/kernel/apic/io_apic.c index 085e60e303cf..b377b973899e 100644 --- a/arch/x86/kernel/apic/io_apic.c +++ b/arch/x86/kernel/apic/io_apic.c @@ -2583,6 +2583,20 @@ static void ack_apic_level(unsigned int irq) */ ack_APIC_irq(); + /* Tail end of version 0x11 I/O APIC bug workaround */ + if (!(v & (1 << (i & 0x1f)))) { + atomic_inc(&irq_mis_count); + + if (use_eoi_reg) + eoi_ioapic_irq(desc); + else { + spin_lock(&ioapic_lock); + __mask_and_edge_IO_APIC_irq(cfg); + __unmask_and_level_IO_APIC_irq(cfg); + spin_unlock(&ioapic_lock); + } + } + /* Now we can move and renable the irq */ if (unlikely(do_unmask_irq)) { /* Only migrate the irq if the ack has been received. @@ -2616,20 +2630,6 @@ static void ack_apic_level(unsigned int irq) move_masked_irq(irq); unmask_IO_APIC_irq_desc(desc); } - - /* Tail end of version 0x11 I/O APIC bug workaround */ - if (!(v & (1 << (i & 0x1f)))) { - atomic_inc(&irq_mis_count); - - if (use_eoi_reg) - eoi_ioapic_irq(desc); - else { - spin_lock(&ioapic_lock); - __mask_and_edge_IO_APIC_irq(cfg); - __unmask_and_level_IO_APIC_irq(cfg); - spin_unlock(&ioapic_lock); - } - } } #ifdef CONFIG_INTR_REMAP