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From: Paolo Bonzini <pbonzini@redhat.com>
To: Jan Kiszka <jan.kiszka@web.de>
Cc: Richard Henderson <rth@twiddle.net>,
	Matthew Ogilvie <mmogilvi_qemu@miniinfo.net>,
	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 11:34:49 +0200	[thread overview]
Message-ID: <504479B9.4010801@redhat.com> (raw)
In-Reply-To: <50446F9A.4070809@web.de>

Il 03/09/2012 10:51, Jan Kiszka ha scritto:
> The only thing that worries me is that we just consider the PC so far
> while the i8259 is also used on different architectures (PPC, MIPS, Alpha?).

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).

BTW, from the palcode it looks like Alpha wants LTIM=1, so it would be nice
to implement that one as well:

  /* ??? MILO initializes the PIC as edge triggered; I do not know how SRM
     initializes them.  However, Linux seems to expect that these are level
     triggered.  That may be a kernel bug, but level triggers are more
     reliable anyway so lets go with that.  */

  /* Initialize level triggers.  The CY82C693UB that's on real alpha
     hardware doesn't have this; this is a PIIX extension.  However,
     QEMU doesn't implement regular level triggers.  */
  outb(0xff, PORT_PIC2_ELCR);
  outb(0xff, PORT_PIC1_ELCR);

Paolo

  parent reply	other threads:[~2012-09-03  9:35 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 [this message]
2012-09-03 10:34       ` Jan Kiszka
2012-09-03 11:11         ` Paolo Bonzini
2012-09-03 11:26           ` Jan Kiszka
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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