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[PULL 1/5] hw/m68k/q800: Don't connect two qemu_irqs directly to the sam
From: |
Laurent Vivier |
Subject: |
[PULL 1/5] hw/m68k/q800: Don't connect two qemu_irqs directly to the same input |
Date: |
Sat, 12 Dec 2020 18:54:54 +0100 |
From: Peter Maydell <peter.maydell@linaro.org>
The q800 board code connects both of the IRQ outputs of the ESCC
to the same pic[3] qemu_irq. Connecting two qemu_irqs outputs directly
to the same input is not valid as it produces subtly wrong behaviour
(for instance if both the IRQ lines are high, and then one goes
low, the PIC input will see this as a high-to-low transition
even though the second IRQ line should still be holding it high).
This kind of wiring needs an explicitly created OR gate; add one.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Laurent Vivier <laurent@vivier.eu>
Message-Id: <20201106235109.7066-2-peter.maydell@linaro.org>
Signed-off-by: Laurent Vivier <laurent@vivier.eu>
---
hw/m68k/q800.c | 12 ++++++++++--
hw/m68k/Kconfig | 1 +
2 files changed, 11 insertions(+), 2 deletions(-)
diff --git a/hw/m68k/q800.c b/hw/m68k/q800.c
index 4db2b9bbc7b4..f9a2be776eb0 100644
--- a/hw/m68k/q800.c
+++ b/hw/m68k/q800.c
@@ -29,6 +29,7 @@
#include "hw/hw.h"
#include "hw/boards.h"
#include "hw/irq.h"
+#include "hw/or-irq.h"
#include "elf.h"
#include "hw/loader.h"
#include "ui/console.h"
@@ -173,6 +174,7 @@ static void q800_init(MachineState *machine)
CPUState *cs;
DeviceState *dev;
DeviceState *via_dev;
+ DeviceState *escc_orgate;
SysBusESPState *sysbus_esp;
ESPState *esp;
SysBusDevice *sysbus;
@@ -285,8 +287,14 @@ static void q800_init(MachineState *machine)
qdev_prop_set_uint32(dev, "chnAtype", 0);
sysbus = SYS_BUS_DEVICE(dev);
sysbus_realize_and_unref(sysbus, &error_fatal);
- sysbus_connect_irq(sysbus, 0, pic[3]);
- sysbus_connect_irq(sysbus, 1, pic[3]);
+
+ /* Logically OR both its IRQs together */
+ escc_orgate = DEVICE(object_new(TYPE_OR_IRQ));
+ object_property_set_int(OBJECT(escc_orgate), "num-lines", 2, &error_fatal);
+ qdev_realize_and_unref(escc_orgate, NULL, &error_fatal);
+ sysbus_connect_irq(sysbus, 0, qdev_get_gpio_in(escc_orgate, 0));
+ sysbus_connect_irq(sysbus, 1, qdev_get_gpio_in(escc_orgate, 1));
+ qdev_connect_gpio_out(DEVICE(escc_orgate), 0, pic[3]);
sysbus_mmio_map(sysbus, 0, SCC_BASE);
/* SCSI */
diff --git a/hw/m68k/Kconfig b/hw/m68k/Kconfig
index c757e7dfa48b..60d7bcfb8f2b 100644
--- a/hw/m68k/Kconfig
+++ b/hw/m68k/Kconfig
@@ -22,3 +22,4 @@ config Q800
select ESCC
select ESP
select DP8393X
+ select OR_IRQ
--
2.29.2
- [PULL 0/5] M68k for 6.0 patches, Laurent Vivier, 2020/12/12
- [PULL 4/5] target/m68k: Add vmstate definition for M68kCPU, Laurent Vivier, 2020/12/12
- [PULL 2/5] hw/m68k/q800.c: Make the GLUE chip an actual QOM device, Laurent Vivier, 2020/12/12
- [PULL 1/5] hw/m68k/q800: Don't connect two qemu_irqs directly to the same input,
Laurent Vivier <=
- [PULL 3/5] target/m68k: remove useless qregs array, Laurent Vivier, 2020/12/12
- [PULL 5/5] m68k: fix some comment spelling errors, Laurent Vivier, 2020/12/12
- Re: [PULL 0/5] M68k for 6.0 patches, Peter Maydell, 2020/12/12