From: Jan Kiszka <jan.kiszka@siemens.com>
To: Paolo Bonzini <pbonzini@redhat.com>
Cc: Richard Henderson <rth@twiddle.net>,
Matthew Ogilvie <mmogilvi_qemu@miniinfo.net>,
"qemu-devel@nongnu.org" <qemu-devel@nongnu.org>
Subject: Re: [Qemu-devel] [PATCH v4 5/5] i8259: fix dynamically masking slave IRQs with IMR register
Date: Mon, 03 Sep 2012 13:26:06 +0200 [thread overview]
Message-ID: <504493CE.8070101@siemens.com> (raw)
In-Reply-To: <50449061.7080100@redhat.com>
On 2012-09-03 13:11, Paolo Bonzini wrote:
> Il 03/09/2012 12:34, Jan Kiszka ha scritto:
>>>> Why is this a problem? All of them use IRQ2 for a cascade, and initialize
>>>> icw3 to 0x4/0x2 (I checked OpenBIOS, rth's palcode for Alpha, and Linux).
>> IRQ2 is already hard-coded in QEMU (we had to patch this for our machine
>> emulation, but less in recent versions), that is not the point. I'm
>> concerned about the behavioral changes we are discussing here, ie. the
>> special handling of cascading interrupt inputs.
>
> Yeah, it's quite interesting that the behavior isn't mentioned in the
> 8259 datasheets. Still in retrospect it's hard to see how it can
> possibly work with edge-triggered cascaded inputs.
As I said: by avoiding the pattern Matthew generated in his test case.
That's not impossible. All the other OSes running fine against out PIC
models are proving this.
Jan
--
Siemens AG, Corporate Technology, CT RTC ITP SDP-DE
Corporate Competence Center Embedded Linux
next prev parent reply other threads:[~2012-09-03 11:26 UTC|newest]
Thread overview: 45+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-09-03 2:56 [Qemu-devel] [PATCH v4 0/5] Running Microport UNIX (ca 1987) Matthew Ogilvie
2012-09-03 2:56 ` [Qemu-devel] [PATCH v4 1/5] fix some debug printf format strings Matthew Ogilvie
2012-09-03 2:56 ` [Qemu-devel] [PATCH v4 2/5] vl: fix -hdachs/-hda argument order parsing issues Matthew Ogilvie
2012-09-03 2:56 ` [Qemu-devel] [PATCH v4 3/5] qemu-options.hx: mention retrace= VGA option Matthew Ogilvie
2012-09-03 2:56 ` [Qemu-devel] [PATCH v4 4/5] vga: add some optional CGA compatibility hacks Matthew Ogilvie
2012-09-03 2:56 ` [Qemu-devel] [PATCH v4 5/5] i8259: fix dynamically masking slave IRQs with IMR register Matthew Ogilvie
2012-09-03 7:08 ` Paolo Bonzini
2012-09-03 8:40 ` Andreas Färber
2012-09-03 14:39 ` Avi Kivity
2012-09-03 15:42 ` Juan Quintela
2012-09-03 15:45 ` Jan Kiszka
2012-09-03 15:52 ` Avi Kivity
2012-09-03 15:54 ` Jan Kiszka
2012-09-03 15:57 ` Avi Kivity
2012-09-03 16:02 ` Jan Kiszka
2012-09-03 16:15 ` Avi Kivity
2012-09-03 16:23 ` Paolo Bonzini
2012-09-03 16:30 ` Avi Kivity
2012-09-03 16:33 ` Paolo Bonzini
2012-09-03 16:40 ` Jan Kiszka
2012-09-03 16:56 ` Paolo Bonzini
2012-09-04 8:16 ` Avi Kivity
2012-09-04 9:15 ` Paolo Bonzini
2012-09-04 9:20 ` Avi Kivity
2012-09-04 9:29 ` BALATON Zoltan
2012-09-04 9:37 ` Avi Kivity
2012-09-04 9:51 ` Jan Kiszka
2012-09-04 10:06 ` Paolo Bonzini
2012-09-04 10:44 ` Avi Kivity
2012-09-03 16:30 ` Jan Kiszka
2012-09-03 8:51 ` Jan Kiszka
2012-09-03 8:53 ` Jan Kiszka
2012-09-03 9:34 ` Paolo Bonzini
2012-09-03 10:34 ` Jan Kiszka
2012-09-03 11:11 ` Paolo Bonzini
2012-09-03 11:26 ` Jan Kiszka [this message]
2012-09-04 14:29 ` Maciej W. Rozycki
2012-09-04 14:42 ` Paolo Bonzini
2012-09-04 16:01 ` Jan Kiszka
2012-09-04 17:41 ` Maciej W. Rozycki
2012-09-04 17:55 ` Jan Kiszka
2012-09-04 18:27 ` Maciej W. Rozycki
2012-09-04 18:39 ` Jan Kiszka
2012-09-05 4:33 ` Matthew Ogilvie
2012-09-05 15:43 ` Jan Kiszka
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