Index: uspace/drv/bus/isa/i8237.c
===================================================================
--- uspace/drv/bus/isa/i8237.c	(revision f77c1c90c1f223647872d5cefa2d86f63bc846d7)
+++ uspace/drv/bus/isa/i8237.c	(revision e211ea04fccf33d4cb2092f630a29e893e096a02)
@@ -279,8 +279,8 @@
  *
  */
-static inline int dma_controller_init(dma_controller_t *controller)
+static inline errno_t dma_controller_init(dma_controller_t *controller)
 {
 	assert(controller);
-	int ret = pio_enable(DMA_CONTROLLER_PAGE_BASE, sizeof(dma_page_regs_t),
+	errno_t ret = pio_enable(DMA_CONTROLLER_PAGE_BASE, sizeof(dma_page_regs_t),
 	    (void **) &controller->page_table);
 	if (ret != EOK)
@@ -339,5 +339,5 @@
  * @return Error code.
  */
-int dma_channel_setup(unsigned int channel, uint32_t pa, uint32_t size,
+errno_t dma_channel_setup(unsigned int channel, uint32_t pa, uint32_t size,
     uint8_t mode)
 {
@@ -454,5 +454,5 @@
  * @return Error code.
  */
-int dma_channel_remain(unsigned channel, size_t *size)
+errno_t dma_channel_remain(unsigned channel, size_t *size)
 {
 	assert(size);
Index: uspace/drv/bus/isa/i8237.h
===================================================================
--- uspace/drv/bus/isa/i8237.h	(revision f77c1c90c1f223647872d5cefa2d86f63bc846d7)
+++ uspace/drv/bus/isa/i8237.h	(revision e211ea04fccf33d4cb2092f630a29e893e096a02)
@@ -38,6 +38,6 @@
 #define DRV_BUS_ISA_I8237_H
 
-extern int dma_channel_setup(unsigned, uint32_t, uint32_t, uint8_t);
-extern int dma_channel_remain(unsigned, size_t *);
+extern errno_t dma_channel_setup(unsigned, uint32_t, uint32_t, uint8_t);
+extern errno_t dma_channel_remain(unsigned, size_t *);
 
 #endif
Index: uspace/drv/bus/isa/isa.c
===================================================================
--- uspace/drv/bus/isa/isa.c	(revision f77c1c90c1f223647872d5cefa2d86f63bc846d7)
+++ uspace/drv/bus/isa/isa.c	(revision e211ea04fccf33d4cb2092f630a29e893e096a02)
@@ -130,5 +130,5 @@
 }
 
-static int isa_fun_enable_interrupt(ddf_fun_t *fnode, int irq)
+static errno_t isa_fun_enable_interrupt(ddf_fun_t *fnode, int irq)
 {
 	isa_fun_t *fun = isa_fun(fnode);
@@ -140,5 +140,5 @@
 }
 
-static int isa_fun_disable_interrupt(ddf_fun_t *fnode, int irq)
+static errno_t isa_fun_disable_interrupt(ddf_fun_t *fnode, int irq)
 {
 	isa_fun_t *fun = isa_fun(fnode);
@@ -150,5 +150,5 @@
 }
 
-static int isa_fun_clear_interrupt(ddf_fun_t *fnode, int irq)
+static errno_t isa_fun_clear_interrupt(ddf_fun_t *fnode, int irq)
 {
 	isa_fun_t *fun = isa_fun(fnode);
@@ -160,5 +160,5 @@
 }
 
-static int isa_fun_setup_dma(ddf_fun_t *fnode,
+static errno_t isa_fun_setup_dma(ddf_fun_t *fnode,
     unsigned int channel, uint32_t pa, uint32_t size, uint8_t mode)
 {
@@ -182,5 +182,5 @@
 }
 
-static int isa_fun_remain_dma(ddf_fun_t *fnode,
+static errno_t isa_fun_remain_dma(ddf_fun_t *fnode,
     unsigned channel, size_t *size)
 {
@@ -232,8 +232,8 @@
 };
 
-static int isa_dev_add(ddf_dev_t *dev);
-static int isa_dev_remove(ddf_dev_t *dev);
-static int isa_fun_online(ddf_fun_t *fun);
-static int isa_fun_offline(ddf_fun_t *fun);
+static errno_t isa_dev_add(ddf_dev_t *dev);
+static errno_t isa_dev_remove(ddf_dev_t *dev);
+static errno_t isa_fun_online(ddf_fun_t *fun);
+static errno_t isa_fun_offline(ddf_fun_t *fun);
 
 /** The isa device driver's standard operations */
@@ -277,5 +277,5 @@
 	int fd;
 	size_t len;
-	int rc;
+	errno_t rc;
 	size_t nread;
 	struct stat st;
@@ -578,5 +578,5 @@
 	    "function %s", id, score, ddf_fun_get_name(fun->fnode));
 
-	int rc = ddf_fun_add_match_id(fun->fnode, id, score);
+	errno_t rc = ddf_fun_add_match_id(fun->fnode, id, score);
 	if (rc != EOK) {
 		ddf_msg(LVL_ERROR, "Failed adding match ID: %s",
@@ -698,8 +698,8 @@
 }
 
-static int isa_dev_add(ddf_dev_t *dev)
+static errno_t isa_dev_add(ddf_dev_t *dev)
 {
 	async_sess_t *sess;
-	int rc;
+	errno_t rc;
 
 	ddf_msg(LVL_DEBUG, "isa_dev_add, device handle = %d",
@@ -767,5 +767,5 @@
 }
 
-static int isa_dev_remove(ddf_dev_t *dev)
+static errno_t isa_dev_remove(ddf_dev_t *dev)
 {
 	isa_bus_t *isa = isa_bus(dev);
@@ -777,5 +777,5 @@
 		    isa_fun_t, bus_link);
 
-		int rc = ddf_fun_offline(fun->fnode);
+		errno_t rc = ddf_fun_offline(fun->fnode);
 		if (rc != EOK) {
 			fibril_mutex_unlock(&isa->mutex);
@@ -807,5 +807,5 @@
 }
 
-static int isa_fun_online(ddf_fun_t *fun)
+static errno_t isa_fun_online(ddf_fun_t *fun)
 {
 	ddf_msg(LVL_DEBUG, "isa_fun_online()");
@@ -813,5 +813,5 @@
 }
 
-static int isa_fun_offline(ddf_fun_t *fun)
+static errno_t isa_fun_offline(ddf_fun_t *fun)
 {
 	ddf_msg(LVL_DEBUG, "isa_fun_offline()");