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[Qemu-devel] Re: [PATCH] ioapic: when switches to level trigger mode, in
From: |
Jan Kiszka |
Subject: |
[Qemu-devel] Re: [PATCH] ioapic: when switches to level trigger mode, interrupts raised repeatedly. |
Date: |
Sat, 09 Apr 2011 10:38:10 +0200 |
User-agent: |
Mozilla/5.0 (X11; U; Linux i686 (x86_64); de; rv:1.8.1.12) Gecko/20080226 SUSE/2.0.0.12-1.1 Thunderbird/2.0.0.12 Mnenhy/0.7.5.666 |
On 2011-04-04 04:15, Isaku Yamahata wrote:
> On Mon, Apr 04, 2011 at 08:42:07AM +0900, Isaku Yamahata wrote:
>> > Thank you for applying. But I found that the patch is wrong and
>> > I'm preparing the new one. Can you please revert it?
> Here is the corrected patch. The first wrong patch clears the interrupts
> bit unconditionally. Which caused losing interrupt.
>
> From 5ed177d35ab14f3b070a0eba2c49400279a3a14b Mon Sep 17 00:00:00 2001
> Message-Id: <address@hidden>
> In-Reply-To: <address@hidden>
> References: <address@hidden>
> From: Isaku Yamahata <address@hidden>
> Date: Wed, 16 Mar 2011 14:00:13 +0900
> Subject: [PATCH 01/30] ioapic: when switches to level trigger mode,
> interrupts raised repeatedly.
>
> - the trigger mode is edge at first by reset.
> - During initializatoin, the interrupt is raised as edge which is masked.
> The corresponding bit of irr is set.
...and that is the actual problem. The spec says: "Interrupt Mask—R/W.
When this bit is 1, the interrupt signal is masked. Edge-sensitive
interrupts signaled on a masked interrupt pin are ignored (i.e., not
delivered or held pending)."
So this should do the trick in a correct way (untested, please
validate):
diff --git a/hw/ioapic.c b/hw/ioapic.c
index 569327d..6663f41 100644
--- a/hw/ioapic.c
+++ b/hw/ioapic.c
@@ -161,7 +161,7 @@ static void ioapic_set_irq(void *opaque, int vector, int
level)
}
} else {
/* edge triggered */
- if (level) {
+ if (level && !(entry & IOAPIC_LVT_MASKED)) {
s->irr |= mask;
ioapic_service(s);
}
Jan
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- Re: [Qemu-devel] [PATCH] ioapic: when switches to level trigger mode, interrupts raised repeatedly., Aurelien Jarno, 2011/04/03
- Re: [Qemu-devel] [PATCH] ioapic: when switches to level trigger mode, interrupts raised repeatedly., Isaku Yamahata, 2011/04/03
- Re: [Qemu-devel] [PATCH] ioapic: when switches to level trigger mode, interrupts raised repeatedly., Isaku Yamahata, 2011/04/03
- [Qemu-devel] Re: [PATCH] ioapic: when switches to level trigger mode, interrupts raised repeatedly.,
Jan Kiszka <=
- [Qemu-devel] Re: [PATCH] ioapic: when switches to level trigger mode, interrupts raised repeatedly., Isaku Yamahata, 2011/04/09
- [Qemu-devel] [PATCH] ioapic: Do not set irr for masked edge IRQs, Jan Kiszka, 2011/04/09
- [Qemu-devel] Re: [PATCH] ioapic: Do not set irr for masked edge IRQs, Jan Kiszka, 2011/04/09
- [Qemu-devel] Re: [PATCH] ioapic: Do not set irr for masked edge IRQs, Jan Kiszka, 2011/04/09
- [Qemu-devel] Re: [PATCH] ioapic: Do not set irr for masked edge IRQs, Isaku Yamahata, 2011/04/09
- Re: [Qemu-devel] [PATCH] ioapic: Do not set irr for masked edge IRQs, Jan Kiszka, 2011/04/26
- Re: [Qemu-devel] [PATCH] ioapic: Do not set irr for masked edge IRQs, Aurelien Jarno, 2011/04/27
Re: [Qemu-devel] [PATCH] ioapic: when switches to level trigger mode, interrupts raised repeatedly., Aurelien Jarno, 2011/04/04