Index: uspace/drv/bus/usb/ohci/hc.c
===================================================================
--- uspace/drv/bus/usb/ohci/hc.c	(revision 45f4f19577155efbab658848098dce36a9ec2b91)
+++ uspace/drv/bus/usb/ohci/hc.c	(revision 1b90e90a1542b2dc46830752d3e32cb9c97b5dfb)
@@ -592,9 +592,8 @@
 	if (instance->hcca == NULL)
 		return ENOMEM;
-	bzero(instance->hcca, sizeof(hcca_t));
 	usb_log_debug2("OHCI HCCA initialized at %p.\n", instance->hcca);
 
-	for (unsigned i = 0; i < 32; ++i) {
-		OHCI_WR(instance->hcca->int_ep[i],
+	for (unsigned i = 0; i < HCCA_INT_EP_COUNT; ++i) {
+		hcca_set_int_ep(instance->hcca, i,
 		    instance->lists[USB_TRANSFER_INTERRUPT].list_head_pa);
 	}
Index: uspace/drv/bus/usb/ohci/hw_struct/hcca.h
===================================================================
--- uspace/drv/bus/usb/ohci/hw_struct/hcca.h	(revision 45f4f19577155efbab658848098dce36a9ec2b91)
+++ uspace/drv/bus/usb/ohci/hw_struct/hcca.h	(revision 1b90e90a1542b2dc46830752d3e32cb9c97b5dfb)
@@ -38,19 +38,49 @@
 #include <malloc.h>
 
+#include "mem_access.h"
+
+#define HCCA_INT_EP_COUNT  32
+
 /** Host controller communication area.
  * Shared memory used for communication between the controller and the driver.
  */
 typedef struct hcca {
-	uint32_t int_ep[32];
+	/** Interrupt endpoints */
+	uint32_t int_ep[HCCA_INT_EP_COUNT];
+	/** Frame number. */
 	uint16_t frame_number;
 	uint16_t pad1;
+	/** Pointer to the last completed TD. (useless) */
 	uint32_t done_head;
+	/** Padding to make the size 256B */
 	uint32_t reserved[29];
 } __attribute__((packed, aligned)) hcca_t;
 
-static inline void * hcca_get(void)
+/** Allocate properly aligned structure.
+ *
+ * The returned structure is zeroed upon allocation.
+ *
+ * @return Usable HCCA memory structure.
+ */
+static inline hcca_t * hcca_get(void)
 {
 	assert(sizeof(hcca_t) == 256);
-	return memalign(256, sizeof(hcca_t));
+	hcca_t *hcca = memalign(256, sizeof(hcca_t));
+	if (hcca)
+		bzero(hcca, sizeof(hcca_t));
+	return hcca;
+}
+
+/** Set HCCA interrupt endpoint pointer table entry.
+ * @param hcca HCCA memory structure.
+ * @param index table index.
+ * @param pa Physical address.
+ */
+static inline void hcca_set_int_ep(hcca_t *hcca, unsigned index, uintptr_t pa)
+{
+	assert(hcca);
+	assert(index < HCCA_INT_EP_COUNT);
+	OHCI_MEM32_WR(hcca->int_ep[index], pa);
+
 }
 #endif
Index: uspace/drv/bus/usb/ohci/root_hub.c
===================================================================
--- uspace/drv/bus/usb/ohci/root_hub.c	(revision 45f4f19577155efbab658848098dce36a9ec2b91)
+++ uspace/drv/bus/usb/ohci/root_hub.c	(revision 1b90e90a1542b2dc46830752d3e32cb9c97b5dfb)
@@ -434,5 +434,5 @@
 			/* Register format matches the format of port status
 			 * field */
-			const uint32_t data = uint32_usb2host(OHCI_RD(
+			const uint32_t data = uint32_host2usb(OHCI_RD(
 			    instance->registers->rh_port_status[port - 1]));
 			TRANSFER_END_DATA(request, &data, sizeof(data));