Index: uspace/lib/usbhost/src/ddf_helpers.c
===================================================================
--- uspace/lib/usbhost/src/ddf_helpers.c	(revision 816f5f48c86652a41469235b97f890a3275083a0)
+++ uspace/lib/usbhost/src/ddf_helpers.c	(revision 60af4cdb1acd8703dcd25885a99082aecd43036f)
@@ -47,5 +47,4 @@
 #include <ddf/interrupt.h>
 #include <device/hw_res_parsed.h>
-#include <devman.h>
 #include <errno.h>
 #include <fibril_synch.h>
@@ -607,34 +606,29 @@
 }
 
-//TODO: Move this to generic ddf?
-/** Call the parent driver with a request to enable interrupts
+//TODO: Cache parent session in HCD
+/** Call the parent driver with a request to enable interrupt
  *
  * @param[in] device Device asking for interrupts
+ * @param[in] inum Interrupt number
  * @return Error code.
  */
-int hcd_ddf_enable_interrupts(ddf_dev_t *device)
-{
-	assert(device);
-	async_sess_t *parent_sess =
-	    devman_parent_device_connect(ddf_dev_get_handle(device),
-	    IPC_FLAG_BLOCKING);
-	const bool enabled = hw_res_enable_interrupt(parent_sess);
-	async_hangup(parent_sess);
-
-	return enabled ? EOK : EIO;
-}
-
-//TODO: Move this to generic ddf?
+int hcd_ddf_enable_interrupt(ddf_dev_t *device, int inum)
+{
+	async_sess_t *parent_sess = ddf_dev_parent_sess_get(device);
+	if (parent_sess == NULL)
+		return EIO;
+
+	return hw_res_enable_interrupt(parent_sess, inum);
+}
+
+//TODO: Cache parent session in HCD
 int hcd_ddf_get_registers(ddf_dev_t *device, hw_res_list_parsed_t *hw_res)
 {
-	assert(device);
-	assert(hw_res);
-
-	async_sess_t *parent_sess =
-	    devman_parent_device_connect(ddf_dev_get_handle(device),
-	    IPC_FLAG_BLOCKING);
+	async_sess_t *parent_sess = ddf_dev_parent_sess_get(device);
+	if (parent_sess == NULL)
+		return EIO;
+
 	hw_res_list_parsed_init(hw_res);
 	const int ret = hw_res_get_list_parsed(parent_sess, hw_res, 0);
-	async_hangup(parent_sess);
 	if (ret != EOK)
 		hw_res_list_parsed_clean(hw_res);
@@ -663,5 +657,6 @@
  * @param[in] gen_irq_code IRQ code generator.
  *
- * @return EOK on success or negative error code
+ * @return IRQ capability handle on success.
+ * @return Negative error code.
  */
 int hcd_ddf_setup_interrupts(ddf_dev_t *device,
@@ -687,22 +682,22 @@
 
 	/* Register handler to avoid interrupt lockup */
-	int ret = register_interrupt_handler(device, irq, handler, &irq_code);
+	const int irq_cap = register_interrupt_handler(device, irq, handler,
+	    &irq_code);
 	irq_code_clean(&irq_code);
-	if (ret != EOK) {
+	if (irq_cap < 0) {
 		usb_log_error("Failed to register interrupt handler: %s.\n",
-		    str_error(ret));
-		return ret;
+		    str_error(irq_cap));
+		return irq_cap;
 	}
 
 	/* Enable interrupts */
-	ret = hcd_ddf_enable_interrupts(device);
+	int ret = hcd_ddf_enable_interrupt(device, irq);
 	if (ret != EOK) {
 		usb_log_error("Failed to enable interrupts: %s.\n",
 		    str_error(ret));
-		unregister_interrupt_handler(device, irq);
+		unregister_interrupt_handler(device, irq_cap);
 		return ret;
 	}
-	assert(irq > 0);
-	return irq;
+	return irq_cap;
 }
 
@@ -796,6 +791,8 @@
 	interrupt_handler_t *irq_handler =
 	    driver->irq_handler ? driver->irq_handler : ddf_hcd_gen_irq_handler;
-	const int irq = hcd_ddf_setup_interrupts(device, &hw_res, irq_handler, driver->irq_code_gen);
-	if (!(irq < 0)) {
+	const int irq_cap = hcd_ddf_setup_interrupts(device, &hw_res,
+	    irq_handler, driver->irq_code_gen);
+	bool irqs_enabled = !(irq_cap < 0);
+	if (irqs_enabled) {
 		usb_log_debug("Hw interrupts enabled.\n");
 	}
@@ -812,5 +809,5 @@
 	/* Start hw driver */
 	if (driver->start)
-		ret = driver->start(hcd, !(irq < 0));
+		ret = driver->start(hcd, irqs_enabled);
 	if (ret != EOK) {
 		usb_log_error("Failed to start HCD: %s.\n", str_error(ret));
@@ -819,5 +816,5 @@
 
 	/* Need working irq replacement to setup root hub */
-	if ((irq < 0) && hcd->ops.status_hook) {
+	if (!irqs_enabled && hcd->ops.status_hook) {
 		hcd->polling_fibril = fibril_create(interrupt_polling, hcd);
 		if (hcd->polling_fibril == 0) {
@@ -828,5 +825,5 @@
 		fibril_add_ready(hcd->polling_fibril);
 		usb_log_warning("Failed to enable interrupts: %s."
-		    " Falling back to polling.\n", str_error(irq));
+		    " Falling back to polling.\n", str_error(irq_cap));
 	}
 
@@ -854,5 +851,5 @@
 		driver->stop(hcd);
 err_irq:
-	unregister_interrupt_handler(device, irq);
+	unregister_interrupt_handler(device, irq_cap);
 	if (driver->fini)
 		driver->fini(hcd);