diff --git a/src/kernel/interrupts/interrupts.c b/src/kernel/interrupts/interrupts.c
index 97006d4..0a02f5a 100644
--- a/src/kernel/interrupts/interrupts.c
+++ b/src/kernel/interrupts/interrupts.c
@@ -88,8 +88,8 @@
     outb(0xA0, 0x11);
     outb(0xA1, 32);
     outb(0x21, 40);
-    outb(0xA1, 0x04);
-    outb(0x21, 0x02);
+    outb(0xA1, 0x02);
+    outb(0x21, 0x04);
     outb(0x21, 0x1);
     outb(0xA1, 0x1);
     outb(0x21, 0xFF);

diff --git a/src/kernel/interrupts/interrupts.c b/src/kernel/interrupts/interrupts.c
index 97006d4..0a02f5a 100644
--- a/src/kernel/interrupts/interrupts.c
+++ b/src/kernel/interrupts/interrupts.c
@@ -88,8 +88,8 @@
     outb(0xA0, 0x11);
     outb(0xA1, 32);
     outb(0x21, 40);
-    outb(0xA1, 0x04);
-    outb(0x21, 0x02);
+    outb(0xA1, 0x02);
+    outb(0x21, 0x04);
     outb(0x21, 0x1);
     outb(0xA1, 0x1);
     outb(0x21, 0xFF);
diff --git a/src/userland/pic/main.c b/src/userland/pic/main.c
index 73309f2..a9b2dc5 100644
--- a/src/userland/pic/main.c
+++ b/src/userland/pic/main.c
@@ -24,8 +24,10 @@
 #define PIC_READ_ISR 0x0B
 uint16_t getISR() {
     ioOut(PIC1, PIC_READ_ISR, 1);
+    uint16_t first = ioIn(PIC1, 1);
     ioOut(PIC2, PIC_READ_ISR, 1);
-    return (ioIn(PIC2, 1) << 8) | ioIn(PIC1, 1);
+    uint16_t second = ioIn(PIC2, 1) << 8;
+    return first | second;
 }
 
 void irqMaster(uint32_t intNo) {

diff --git a/src/kernel/interrupts/interrupts.c b/src/kernel/interrupts/interrupts.c
index 97006d4..0a02f5a 100644
--- a/src/kernel/interrupts/interrupts.c
+++ b/src/kernel/interrupts/interrupts.c
@@ -88,8 +88,8 @@
     outb(0xA0, 0x11);
     outb(0xA1, 32);
     outb(0x21, 40);
-    outb(0xA1, 0x04);
-    outb(0x21, 0x02);
+    outb(0xA1, 0x02);
+    outb(0x21, 0x04);
     outb(0x21, 0x1);
     outb(0xA1, 0x1);
     outb(0x21, 0xFF);
diff --git a/src/userland/pic/main.c b/src/userland/pic/main.c
index 73309f2..a9b2dc5 100644
--- a/src/userland/pic/main.c
+++ b/src/userland/pic/main.c
@@ -24,8 +24,10 @@
 #define PIC_READ_ISR 0x0B
 uint16_t getISR() {
     ioOut(PIC1, PIC_READ_ISR, 1);
+    uint16_t first = ioIn(PIC1, 1);
     ioOut(PIC2, PIC_READ_ISR, 1);
-    return (ioIn(PIC2, 1) << 8) | ioIn(PIC1, 1);
+    uint16_t second = ioIn(PIC2, 1) << 8;
+    return first | second;
 }
 
 void irqMaster(uint32_t intNo) {
diff --git a/src/userland/usb/main.c b/src/userland/usb/main.c
index b9e6d76..64dd69f 100644
--- a/src/userland/usb/main.c
+++ b/src/userland/usb/main.c
@@ -3,8 +3,8 @@
 
 #include "usb.h"
 
-void xhci_command(XHCIController *controller, uint32_t p1, uint32_t p2,
-                  uint32_t status, uint32_t control) {
+void xhciCommand(XHCIController *controller, uint32_t p1, uint32_t p2,
+                 uint32_t status, uint32_t control) {
     control &= ~1;
     control |= controller->commands.cycle;
 
@@ -57,8 +57,8 @@
 }
 
 XHCITRB *trbRingFetch(TrbRing *ring) {
-    while ((ring->trbs[ring->dequeue].control & 1) != ring->cycle) {
-        syscall(-1, 0, 0, 0, 0);
+    if ((ring->trbs[ring->dequeue].control & 1) != ring->cycle) {
+        return NULL;
     }
     XHCITRB *result = &ring->trbs[ring->dequeue];
     ring->dequeue++;
@@ -86,8 +86,6 @@
 void setupRuntime(XHCIController *controller) {
     controller->runtime = OFFSET(controller->capabilities,
                                  controller->capabilities->runtimeOffset);
-    controller->runtime->interrupters[0].enabled = true;
-    controller->runtime->interrupters[0].moderationCounter = 500;
     controller->runtime->interrupters[0].eventRingSegmentTableSize = 1;
     controller->runtime->interrupters[0].eventRingSegmentTableAddress[0] =
         U32(controller->eventRingSegmentTablePhysical);
@@ -96,6 +94,9 @@
         U32(&controller->events.physical[controller->events.dequeue]) |
         (1 << 3);
     controller->runtime->interrupters[0].eventRingDequeuePointer[1] = 0;
+
+    controller->runtime->interrupters[0].management |= 3;
+    sleep(100);
 }
 
 void setupEventRingSegmentTable(XHCIController *controller) {
@@ -192,33 +193,15 @@
            slotInfo >> 24);
     return controller;
 }
+XHCIController *controller;
 
-static void initializeUSB(uint32_t deviceId) {
-    XHCIController *controller = initializeController(deviceId);
-    restartXHCIController(controller);
-
-    setupTrbRing(&controller->commands, 256);
-    setupTrbRing(&controller->events, 256);
-    readExtendedCapabilities(controller);
-    setupOperationalRegisters(controller);
-    setupEventRingSegmentTable(controller);
-    setupRuntime(controller);
-    setupScratchpadBuffers(controller);
-
-    controller->operational->command |= (1 << 0) | (1 << 2);
-    sleep(100);
-
-    if (controller->operational->status & (1 << 2))
-        return printf("critical XHCI problem\n");
-
-    // just testing for now...
-    xhci_command(controller, 0, 0, 0, (9 << 10));
-    xhci_command(controller, 0, 0, 0, (9 << 10));
-    xhci_command(controller, 0, 0, 0, (9 << 10));
-    xhci_command(controller, 0, 0, 0, (9 << 10));
-
-    while (1) {
-        XHCITRB *trb = trbRingFetch(&controller->events);
+void xhciInterrupt() {
+    if (!(controller->runtime->interrupters[0].management & 1)) {
+        printf("no interrupt pending\n");
+        return;
+    }
+    XHCITRB *trb;
+    while ((trb = trbRingFetch(&controller->events))) {
         uint32_t type = (trb->control >> 10) & 0x3F;
 
         printf("event %i [%x %x %x %x] type: %i, slotId: %i\n",
@@ -231,6 +214,35 @@
     }
 }
 
+void initializeUSB(uint32_t deviceId) {
+    controller = initializeController(deviceId);
+    restartXHCIController(controller);
+
+    setupTrbRing(&controller->commands, 256);
+    setupTrbRing(&controller->events, 256);
+    readExtendedCapabilities(controller);
+    setupOperationalRegisters(controller);
+    setupEventRingSegmentTable(controller);
+    setupRuntime(controller);
+    setupScratchpadBuffers(controller);
+
+    controller->operational->status |= (1 << 3);
+    controller->operational->command |= (1 << 0) | (1 << 2);
+    printf("using irq no. %i\n", getPCIInterrupt(deviceId, 0));
+    int pic = getService("pic");
+    subscribeEvent(pic, getEvent(pic, "irq11"), xhciInterrupt);
+    sleep(100);
+
+    if (controller->operational->status & (1 << 2))
+        return printf("critical XHCI problem\n");
+
+    // just testing for now...
+    xhciCommand(controller, 0, 0, 0, (9 << 10));
+    xhciCommand(controller, 0, 0, 0, (9 << 10));
+    xhciCommand(controller, 0, 0, 0, (9 << 10));
+    xhciCommand(controller, 0, 0, 0, (9 << 10));
+}
+
 int32_t main() {
     uint32_t i = 0, class = 0;
     while ((class = getDeviceClass(i, 0))) {

diff --git a/src/kernel/interrupts/interrupts.c b/src/kernel/interrupts/interrupts.c
index 97006d4..0a02f5a 100644
--- a/src/kernel/interrupts/interrupts.c
+++ b/src/kernel/interrupts/interrupts.c
@@ -88,8 +88,8 @@
     outb(0xA0, 0x11);
     outb(0xA1, 32);
     outb(0x21, 40);
-    outb(0xA1, 0x04);
-    outb(0x21, 0x02);
+    outb(0xA1, 0x02);
+    outb(0x21, 0x04);
     outb(0x21, 0x1);
     outb(0xA1, 0x1);
     outb(0x21, 0xFF);
diff --git a/src/userland/pic/main.c b/src/userland/pic/main.c
index 73309f2..a9b2dc5 100644
--- a/src/userland/pic/main.c
+++ b/src/userland/pic/main.c
@@ -24,8 +24,10 @@
 #define PIC_READ_ISR 0x0B
 uint16_t getISR() {
     ioOut(PIC1, PIC_READ_ISR, 1);
+    uint16_t first = ioIn(PIC1, 1);
     ioOut(PIC2, PIC_READ_ISR, 1);
-    return (ioIn(PIC2, 1) << 8) | ioIn(PIC1, 1);
+    uint16_t second = ioIn(PIC2, 1) << 8;
+    return first | second;
 }
 
 void irqMaster(uint32_t intNo) {
diff --git a/src/userland/usb/main.c b/src/userland/usb/main.c
index b9e6d76..64dd69f 100644
--- a/src/userland/usb/main.c
+++ b/src/userland/usb/main.c
@@ -3,8 +3,8 @@
 
 #include "usb.h"
 
-void xhci_command(XHCIController *controller, uint32_t p1, uint32_t p2,
-                  uint32_t status, uint32_t control) {
+void xhciCommand(XHCIController *controller, uint32_t p1, uint32_t p2,
+                 uint32_t status, uint32_t control) {
     control &= ~1;
     control |= controller->commands.cycle;
 
@@ -57,8 +57,8 @@
 }
 
 XHCITRB *trbRingFetch(TrbRing *ring) {
-    while ((ring->trbs[ring->dequeue].control & 1) != ring->cycle) {
-        syscall(-1, 0, 0, 0, 0);
+    if ((ring->trbs[ring->dequeue].control & 1) != ring->cycle) {
+        return NULL;
     }
     XHCITRB *result = &ring->trbs[ring->dequeue];
     ring->dequeue++;
@@ -86,8 +86,6 @@
 void setupRuntime(XHCIController *controller) {
     controller->runtime = OFFSET(controller->capabilities,
                                  controller->capabilities->runtimeOffset);
-    controller->runtime->interrupters[0].enabled = true;
-    controller->runtime->interrupters[0].moderationCounter = 500;
     controller->runtime->interrupters[0].eventRingSegmentTableSize = 1;
     controller->runtime->interrupters[0].eventRingSegmentTableAddress[0] =
         U32(controller->eventRingSegmentTablePhysical);
@@ -96,6 +94,9 @@
         U32(&controller->events.physical[controller->events.dequeue]) |
         (1 << 3);
     controller->runtime->interrupters[0].eventRingDequeuePointer[1] = 0;
+
+    controller->runtime->interrupters[0].management |= 3;
+    sleep(100);
 }
 
 void setupEventRingSegmentTable(XHCIController *controller) {
@@ -192,33 +193,15 @@
            slotInfo >> 24);
     return controller;
 }
+XHCIController *controller;
 
-static void initializeUSB(uint32_t deviceId) {
-    XHCIController *controller = initializeController(deviceId);
-    restartXHCIController(controller);
-
-    setupTrbRing(&controller->commands, 256);
-    setupTrbRing(&controller->events, 256);
-    readExtendedCapabilities(controller);
-    setupOperationalRegisters(controller);
-    setupEventRingSegmentTable(controller);
-    setupRuntime(controller);
-    setupScratchpadBuffers(controller);
-
-    controller->operational->command |= (1 << 0) | (1 << 2);
-    sleep(100);
-
-    if (controller->operational->status & (1 << 2))
-        return printf("critical XHCI problem\n");
-
-    // just testing for now...
-    xhci_command(controller, 0, 0, 0, (9 << 10));
-    xhci_command(controller, 0, 0, 0, (9 << 10));
-    xhci_command(controller, 0, 0, 0, (9 << 10));
-    xhci_command(controller, 0, 0, 0, (9 << 10));
-
-    while (1) {
-        XHCITRB *trb = trbRingFetch(&controller->events);
+void xhciInterrupt() {
+    if (!(controller->runtime->interrupters[0].management & 1)) {
+        printf("no interrupt pending\n");
+        return;
+    }
+    XHCITRB *trb;
+    while ((trb = trbRingFetch(&controller->events))) {
         uint32_t type = (trb->control >> 10) & 0x3F;
 
         printf("event %i [%x %x %x %x] type: %i, slotId: %i\n",
@@ -231,6 +214,35 @@
     }
 }
 
+void initializeUSB(uint32_t deviceId) {
+    controller = initializeController(deviceId);
+    restartXHCIController(controller);
+
+    setupTrbRing(&controller->commands, 256);
+    setupTrbRing(&controller->events, 256);
+    readExtendedCapabilities(controller);
+    setupOperationalRegisters(controller);
+    setupEventRingSegmentTable(controller);
+    setupRuntime(controller);
+    setupScratchpadBuffers(controller);
+
+    controller->operational->status |= (1 << 3);
+    controller->operational->command |= (1 << 0) | (1 << 2);
+    printf("using irq no. %i\n", getPCIInterrupt(deviceId, 0));
+    int pic = getService("pic");
+    subscribeEvent(pic, getEvent(pic, "irq11"), xhciInterrupt);
+    sleep(100);
+
+    if (controller->operational->status & (1 << 2))
+        return printf("critical XHCI problem\n");
+
+    // just testing for now...
+    xhciCommand(controller, 0, 0, 0, (9 << 10));
+    xhciCommand(controller, 0, 0, 0, (9 << 10));
+    xhciCommand(controller, 0, 0, 0, (9 << 10));
+    xhciCommand(controller, 0, 0, 0, (9 << 10));
+}
+
 int32_t main() {
     uint32_t i = 0, class = 0;
     while ((class = getDeviceClass(i, 0))) {
diff --git a/src/userland/usb/usb.h b/src/userland/usb/usb.h
index f7550c8..bad390b 100644
--- a/src/userland/usb/usb.h
+++ b/src/userland/usb/usb.h
@@ -28,7 +28,7 @@
     uint32_t status;
     uint32_t pageSize;
     uint32_t reserved[2];
-    uint32_t op_dnctrl;
+    uint32_t notification;
     uint32_t commandRingControl[2];
     uint32_t reserved1[4];
     uint32_t deviceContextBaseAddressArray[2];
@@ -45,7 +45,7 @@
 } __attribute__((packed)) XHCITRB;
 
 typedef volatile struct {
-    uint32_t pending : 1, enabled : 1, reserved : 30;
+    uint32_t management;
     uint32_t moderationCounter : 16, moderationInterval : 16;
     uint32_t eventRingSegmentTableSize; // MAX 16 bit
     uint32_t reserved2;