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authorPhilippe Mathieu-Daudé <f4bug@amsat.org>2020-11-07 20:34:02 +0100
committerPeter Maydell <peter.maydell@linaro.org>2020-11-10 11:03:48 +0000
commit498661dd22a1b60461e41d256a7197fea3c4ff0e (patch)
tree0d69ccb773d282ea929b6b789f963f7b9bf9be88 /hw/arm/musicpal.c
parentbdad3654d3c55f478e538037d9eccd204e5fc8ee (diff)
downloadfocaccia-qemu-498661dd22a1b60461e41d256a7197fea3c4ff0e.tar.gz
focaccia-qemu-498661dd22a1b60461e41d256a7197fea3c4ff0e.zip
hw/arm/musicpal: Don't connect two qemu_irqs directly to the same input
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>
Diffstat (limited to 'hw/arm/musicpal.c')
-rw-r--r--hw/arm/musicpal.c17
1 files changed, 13 insertions, 4 deletions
diff --git a/hw/arm/musicpal.c b/hw/arm/musicpal.c
index 5eb3f969fb..ebc3ec24ef 100644
--- a/hw/arm/musicpal.c
+++ b/hw/arm/musicpal.c
@@ -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 */