diff options
| author | Peter Maydell <peter.maydell@linaro.org> | 2020-11-06 23:51:08 +0000 |
|---|---|---|
| committer | Laurent Vivier <laurent@vivier.eu> | 2020-12-12 18:05:30 +0100 |
| commit | 9526486164818f1c59a142dec8a1f09fbf77669c (patch) | |
| tree | 7785400e4e3ba3fdfa1bed3e149ea6e8eefb82c9 /hw/m68k | |
| parent | ad717e6da3852b5729217d7938eecdb81c546114 (diff) | |
hw/m68k/q800: Don't connect two qemu_irqs directly to the same input
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>
Diffstat (limited to 'hw/m68k')
| -rw-r--r-- | hw/m68k/Kconfig | 1 | ||||
| -rw-r--r-- | hw/m68k/q800.c | 12 |
2 files changed, 11 insertions, 2 deletions
diff --git a/hw/m68k/Kconfig b/hw/m68k/Kconfig index c757e7dfa4..60d7bcfb8f 100644 --- a/hw/m68k/Kconfig +++ b/hw/m68k/Kconfig @@ -22,3 +22,4 @@ config Q800 select ESCC select ESP select DP8393X + select OR_IRQ diff --git a/hw/m68k/q800.c b/hw/m68k/q800.c index 4db2b9bbc7..f9a2be776e 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 */ |