2007-02-26 22:59:23

by Simon Arlott

[permalink] [raw]
Subject: [irq: Remove set_native_irq_info] !CONFIG_SMP regression

9f0a5ba5508143731dc63235de19659be20d26dc is first bad commit
commit 9f0a5ba5508143731dc63235de19659be20d26dc
Author: Eric W. Biederman <[email protected]>
Date: Fri Feb 23 04:13:55 2007 -0700

[PATCH] irq: Remove set_native_irq_info

This patch replaces all instances of "set_native_irq_info(irq, mask)"
with "irq_desc[irq].affinity = mask". The latter form is clearer
uses fewer abstractions, and makes access to this field uniform
accross different architectures.



arch/i386/kernel/io_apic.c: In function `setup_IO_APIC_irqs':
arch/i386/kernel/io_apic.c:1357: error: structure has no member named `affinity'
arch/i386/kernel/io_apic.c: In function `io_apic_set_pci_routing':
arch/i386/kernel/io_apic.c:2878: error: structure has no member named `affinity'


The original version was an empty function if !CONFIG_SMP, struct irq_desc only has 'affinity' on SMP.

--
Simon Arlott


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2007-02-26 23:50:57

by Eric W. Biederman

[permalink] [raw]
Subject: Re: [irq: Remove set_native_irq_info] !CONFIG_SMP regression

Simon Arlott <[email protected]> writes:

> 9f0a5ba5508143731dc63235de19659be20d26dc is first bad commit
> commit 9f0a5ba5508143731dc63235de19659be20d26dc
> Author: Eric W. Biederman <[email protected]>
> Date: Fri Feb 23 04:13:55 2007 -0700
>
> [PATCH] irq: Remove set_native_irq_info
>
> This patch replaces all instances of "set_native_irq_info(irq, mask)"
> with "irq_desc[irq].affinity = mask". The latter form is clearer
> uses fewer abstractions, and makes access to this field uniform
> accross different architectures.
>
>
>
> arch/i386/kernel/io_apic.c: In function `setup_IO_APIC_irqs':
> arch/i386/kernel/io_apic.c:1357: error: structure has no member named `affinity'
> arch/i386/kernel/io_apic.c: In function `io_apic_set_pci_routing':
> arch/i386/kernel/io_apic.c:2878: error: structure has no member named `affinity'
>
>
> The original version was an empty function if !CONFIG_SMP, struct irq_desc only
> has 'affinity' on SMP.

Yep.

Give me a bit. I think we can just kill those lines.

Eric

2007-02-27 07:28:21

by Eric W. Biederman

[permalink] [raw]
Subject: [PATCH] x86_64/i386 irq: Fix !CONFIG_SMP compilation


When removing set_native_irq I missed the fact that it was
called in a couple of places that were compiled even when
SMP support is disabled. And since the irq_desc[].affinity
field only exists in SMP things broke.

Thanks to Simon Arlott <[email protected]> for spotting this.

There are a couple of ways to fix this but the simplest one
is to just remove the assignments. The affinity field is only
used to display a value to the user, and nothing on either i386
or x86_64 reads it or depends on it being any particlua value,
so skipping the assignment is safe. The assignment that
is being removed is just for the initial affinity value before
the user explicitly sets it. The irq_desc array initializes
this field to CPU_MASK_ALL so the field is initialized to
a reasonable value in the SMP case without being set.

Signed-off-by: Eric W. Biederman <[email protected]>
---
arch/i386/kernel/io_apic.c | 2 --
arch/x86_64/kernel/io_apic.c | 4 ----
2 files changed, 0 insertions(+), 6 deletions(-)

diff --git a/arch/i386/kernel/io_apic.c b/arch/i386/kernel/io_apic.c
index 6fec4da..e4408ff 100644
--- a/arch/i386/kernel/io_apic.c
+++ b/arch/i386/kernel/io_apic.c
@@ -1354,7 +1354,6 @@ static void __init setup_IO_APIC_irqs(void)
}
spin_lock_irqsave(&ioapic_lock, flags);
__ioapic_write_entry(apic, pin, entry);
- irq_desc[irq].affinity = TARGET_CPUS;
spin_unlock_irqrestore(&ioapic_lock, flags);
}
}
@@ -2875,7 +2874,6 @@ int io_apic_set_pci_routing (int ioapic, int pin, int irq, int edge_level, int a

spin_lock_irqsave(&ioapic_lock, flags);
__ioapic_write_entry(ioapic, pin, entry);
- irq_desc[irq].affinity = TARGET_CPUS;
spin_unlock_irqrestore(&ioapic_lock, flags);

return 0;
diff --git a/arch/x86_64/kernel/io_apic.c b/arch/x86_64/kernel/io_apic.c
index 48593f6..0a91368 100644
--- a/arch/x86_64/kernel/io_apic.c
+++ b/arch/x86_64/kernel/io_apic.c
@@ -830,10 +830,6 @@ static void setup_IO_APIC_irq(int apic, int pin, unsigned int irq,
disable_8259A_irq(irq);

ioapic_write_entry(apic, pin, entry);
-
- spin_lock_irqsave(&ioapic_lock, flags);
- irq_desc[irq].affinity = TARGET_CPUS;
- spin_unlock_irqrestore(&ioapic_lock, flags);
}

static void __init setup_IO_APIC_irqs(void)
--
1.5.0.g53756