Index: uspace/drv/bus/usb/ohci/root_hub.c
===================================================================
--- uspace/drv/bus/usb/ohci/root_hub.c	(revision dab311200f066c27dc908a2d866a746a7737d747)
+++ uspace/drv/bus/usb/ohci/root_hub.c	(revision 0fe2ff1066bd20d937f5ffb8589c4a6d74ca42ce)
@@ -108,11 +108,13 @@
 static void create_serialized_hub_descriptor(rh_t *instance);
 static void rh_init_descriptors(rh_t *instance);
-static uint16_t create_interrupt_mask(rh_t *instance);
-static int get_status(rh_t *instance, usb_transfer_batch_t *request);
-static int get_descriptor(rh_t *instance, usb_transfer_batch_t *request);
-static int set_feature(rh_t *instance, usb_transfer_batch_t *request);
-static int clear_feature(rh_t *instance, usb_transfer_batch_t *request);
-static int set_feature_port(rh_t *instance, uint16_t feature, uint16_t port);
-static int clear_feature_port(rh_t *instance, uint16_t feature, uint16_t port);
+static uint16_t create_interrupt_mask(const rh_t *instance);
+static int get_status(const rh_t *instance, usb_transfer_batch_t *request);
+static int get_descriptor(const rh_t *instance, usb_transfer_batch_t *request);
+static int set_feature(const rh_t *instance, usb_transfer_batch_t *request);
+static int clear_feature(const rh_t *instance, usb_transfer_batch_t *request);
+static int set_feature_port(
+    const rh_t *instance, uint16_t feature, uint16_t port);
+static int clear_feature_port(
+    const rh_t *instance, uint16_t feature, uint16_t port);
 static int control_request(rh_t *instance, usb_transfer_batch_t *request);
 static inline void interrupt_request(
@@ -153,9 +155,11 @@
 	instance->unfinished_interrupt_transfer = NULL;
 
-#ifdef OHCI_POWER_SWITCH_no
+#if defined OHCI_POWER_SWITCH_no
 	/* Set port power mode to no power-switching. (always on) */
 	instance->registers->rh_desc_a |= RHDA_NPS_FLAG;
+
 	/* Set to no over-current reporting */
 	instance->registers->rh_desc_a |= RHDA_NOCP_FLAG;
+
 #elif defined OHCI_POWER_SWITCH_ganged
 	/* Set port power mode to no ganged power-switching. */
@@ -163,4 +167,5 @@
 	instance->registers->rh_desc_a &= ~RHDA_PSM_FLAG;
 	instance->registers->rh_status = RHS_CLEAR_GLOBAL_POWER;
+
 	/* Set to global over-current */
 	instance->registers->rh_desc_a &= ~RHDA_NOCP_FLAG;
@@ -174,7 +179,9 @@
 	instance->registers->rh_desc_b &= (RHDB_PCC_MASK << RHDB_PCC_SHIFT);
 	instance->registers->rh_status = RHS_CLEAR_GLOBAL_POWER;
+
 	/* Return control to per port state */
 	instance->registers->rh_desc_b |=
 		((1 << (instance->port_count + 1)) - 1) << RHDB_PCC_SHIFT;
+
 	/* Set per port over-current */
 	instance->registers->rh_desc_a &= ~RHDA_NOCP_FLAG;
@@ -342,5 +349,5 @@
  * @return Mask of changes.
  */
-uint16_t create_interrupt_mask(rh_t *instance)
+uint16_t create_interrupt_mask(const rh_t *instance)
 {
 	assert(instance);
@@ -372,5 +379,5 @@
  * @return error code
  */
-int get_status(rh_t *instance, usb_transfer_batch_t *request)
+int get_status(const rh_t *instance, usb_transfer_batch_t *request)
 {
 	assert(instance);
@@ -418,5 +425,5 @@
  * @return Error code
  */
-int get_descriptor(rh_t *instance, usb_transfer_batch_t *request)
+int get_descriptor(const rh_t *instance, usb_transfer_batch_t *request)
 {
 	assert(instance);
@@ -496,5 +503,5 @@
  * @return error code
  */
-int set_feature_port(rh_t *instance, uint16_t feature, uint16_t port)
+int set_feature_port(const rh_t *instance, uint16_t feature, uint16_t port)
 {
 	assert(instance);
@@ -535,5 +542,5 @@
  * @return error code
  */
-int clear_feature_port(rh_t *instance, uint16_t feature, uint16_t port)
+int clear_feature_port(const rh_t *instance, uint16_t feature, uint16_t port)
 {
 	assert(instance);
@@ -592,5 +599,5 @@
  * @return error code
  */
-int set_feature(rh_t *instance, usb_transfer_batch_t *request)
+int set_feature(const rh_t *instance, usb_transfer_batch_t *request)
 {
 	assert(instance);
@@ -628,5 +635,5 @@
  * @return error code
  */
-int clear_feature(rh_t *instance, usb_transfer_batch_t *request)
+int clear_feature(const rh_t *instance, usb_transfer_batch_t *request)
 {
 	assert(instance);
@@ -635,5 +642,7 @@
 	const usb_device_request_setup_packet_t *setup_request =
 	    (usb_device_request_setup_packet_t *) request->setup_buffer;
+
 	request->transfered_size = 0;
+
 	switch (setup_request->request_type)
 	{
@@ -647,6 +656,7 @@
 		/*
 		 * Chapter 11.16.2 specifies that only C_HUB_LOCAL_POWER and
-		 * C_HUB_OVER_CURRENT are supported. C_HUB_OVER_CURRENT is represented
-		 * by OHCI RHS_OCIC_FLAG. C_HUB_LOCAL_POWER is not supported
+		 * C_HUB_OVER_CURRENT are supported.
+		 * C_HUB_OVER_CURRENT is represented by OHCI RHS_OCIC_FLAG.
+		 * C_HUB_LOCAL_POWER is not supported
 		 * as root hubs do not support local power status feature.
 		 * (OHCI pg. 127) */
@@ -720,4 +730,5 @@
 		    "additional data\n");
 		return clear_feature(instance, request);
+
 	case USB_DEVREQ_SET_FEATURE:
 		usb_log_debug2("Processing request without "