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hw/arm/musicpal: Don't connect two qemu_irqs directly to the same input

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The MusicPal board code connects both of the IRQ outputs of the UART
to the same INTC 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 INTC 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.

Inspired-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Message-id: 20201107193403.436146-5-f4bug@amsat.org
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
This commit is contained in:
Philippe Mathieu-Daudé 2020-11-07 20:34:02 +01:00 committed by Peter Maydell
parent bdad3654d3
commit 498661dd22
2 changed files with 14 additions and 4 deletions
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1
hw/arm/Kconfig
View File

@ -93,6 +93,7 @@ config MUSCA
config MUSICPAL
bool
select OR_IRQ
select BITBANG_I2C
select MARVELL_88W8618
select PTIMER

17
hw/arm/musicpal.c
View File

@ -27,6 +27,7 @@
#include "ui/console.h"
#include "hw/i2c/i2c.h"
#include "hw/irq.h"
#include "hw/or-irq.h"
#include "hw/audio/wm8750.h"
#include "sysemu/block-backend.h"
#include "sysemu/runstate.h"
@ -77,8 +78,7 @@
#define MP_TIMER4_IRQ 7
#define MP_EHCI_IRQ 8
#define MP_ETH_IRQ 9
#define MP_UART1_IRQ 11
#define MP_UART2_IRQ 11
#define MP_UART_SHARED_IRQ 11
#define MP_GPIO_IRQ 12
#define MP_RTC_IRQ 28
#define MP_AUDIO_IRQ 30
@ -1589,6 +1589,7 @@ static void musicpal_init(MachineState *machine)
ARMCPU *cpu;
qemu_irq pic[32];
DeviceState *dev;
DeviceState *uart_orgate;
DeviceState *i2c_dev;
DeviceState *lcd_dev;
DeviceState *key_dev;
@ -1627,9 +1628,17 @@ static void musicpal_init(MachineState *machine)
pic[MP_TIMER2_IRQ], pic[MP_TIMER3_IRQ],
pic[MP_TIMER4_IRQ], NULL);
serial_mm_init(address_space_mem, MP_UART1_BASE, 2, pic[MP_UART1_IRQ],
/* Logically OR both UART IRQs together */
uart_orgate = DEVICE(object_new(TYPE_OR_IRQ));
object_property_set_int(OBJECT(uart_orgate), "num-lines", 2, &error_fatal);
qdev_realize_and_unref(uart_orgate, NULL, &error_fatal);
qdev_connect_gpio_out(DEVICE(uart_orgate), 0, pic[MP_UART_SHARED_IRQ]);
serial_mm_init(address_space_mem, MP_UART1_BASE, 2,
qdev_get_gpio_in(uart_orgate, 0),
1825000, serial_hd(0), DEVICE_NATIVE_ENDIAN);
serial_mm_init(address_space_mem, MP_UART2_BASE, 2, pic[MP_UART2_IRQ],
serial_mm_init(address_space_mem, MP_UART2_BASE, 2,
qdev_get_gpio_in(uart_orgate, 1),
1825000, serial_hd(1), DEVICE_NATIVE_ENDIAN);
/* Register flash */