diff --git a/drivers/1wire/1wire.c b/drivers/1wire/1wire.c
index f793dbf420..3f86bf58ea 100644
--- a/drivers/1wire/1wire.c
+++ b/drivers/1wire/1wire.c
@@ -143,7 +143,7 @@ static inline void onewire_sem_destroy(FAR struct onewire_sem_s *sem)
   nxsem_destroy(&sem->sem);
 }
 
-/************************************************************************************
+/****************************************************************************
  * Name: onewire_pm_prepare
  *
  * Description:
@@ -170,7 +170,7 @@ static inline void onewire_sem_destroy(FAR struct onewire_sem_s *sem)
  *   power state change).  Drivers are not permitted to return non-zero
  *   values when reverting back to higher power consumption modes!
  *
- ************************************************************************************/
+ ****************************************************************************/
 #ifdef CONFIG_PM
 static int onewire_pm_prepare(FAR struct pm_callback_s *cb, int domain,
                               enum pm_state_e pmstate)
@@ -190,6 +190,7 @@ static int onewire_pm_prepare(FAR struct pm_callback_s *cb, int domain,
 
     case PM_STANDBY:
     case PM_SLEEP:
+
       /* Check if exclusive lock for the bus master is held. */
 
       if (nxsem_getvalue(&master->devsem.sem, &sval) < 0)
@@ -208,6 +209,7 @@ static int onewire_pm_prepare(FAR struct pm_callback_s *cb, int domain,
       break;
 
     default:
+
       /* Should not get here */
 
       break;
@@ -229,9 +231,10 @@ static int onewire_pm_prepare(FAR struct pm_callback_s *cb, int domain,
  *
  ****************************************************************************/
 
-void onewire_sem_wait(FAR struct onewire_master_s *master)
+int onewire_sem_wait(FAR struct onewire_master_s *master)
 {
   pid_t me;
+  int ret;
 
   /* Do we already hold the semaphore? */
 
@@ -248,13 +251,19 @@ void onewire_sem_wait(FAR struct onewire_master_s *master)
 
   else
     {
-      nxsem_wait_uninterruptible(&master->devsem.sem);
+      ret = nxsem_wait(master->devsem.sem);
+      if (ret < 0)
+        {
+          return ret;
+        }
 
       /* Now we hold the semaphore */
 
       master->devsem.holder = me;
       master->devsem.count  = 1;
     }
+
+  return OK;
 }
 
 /****************************************************************************
@@ -298,7 +307,10 @@ void onewire_sem_post(FAR struct onewire_master_s *master)
 int onewire_reset_resume(FAR struct onewire_master_s *master)
 {
   int ret;
-  uint8_t buf[] = { ONEWIRE_CMD_RESUME };
+  uint8_t buf[] =
+  {
+    ONEWIRE_CMD_RESUME
+  };
 
   ret = ONEWIRE_RESET(master->dev);
   if (ret < 0)
@@ -320,8 +332,16 @@ int onewire_reset_select(FAR struct onewire_slave_s *slave)
 {
   FAR struct onewire_master_s *master = slave->master;
   uint64_t tmp;
-  uint8_t skip_rom[1] = { ONEWIRE_CMD_SKIP_ROM };
-  uint8_t match_rom[9] = { ONEWIRE_CMD_MATCH_ROM, 0 };
+  uint8_t skip_rom[1] =
+  {
+    ONEWIRE_CMD_SKIP_ROM
+  };
+
+  uint8_t match_rom[9] =
+  {
+    ONEWIRE_CMD_MATCH_ROM, 0
+  };
+
   int ret;
 
   ret = ONEWIRE_RESET(master->dev);
@@ -355,8 +375,16 @@ int onewire_reset_select(FAR struct onewire_slave_s *slave)
 
 int onewire_readrom(FAR struct onewire_master_s *master, FAR uint64_t *rom)
 {
-  uint8_t txbuf[] = { ONEWIRE_CMD_READ_ROM };
-  uint8_t rxbuf[8] = { 0 };
+  uint8_t txbuf[] =
+  {
+    ONEWIRE_CMD_READ_ROM
+  };
+
+  uint8_t rxbuf[8] =
+  {
+    0
+  };
+
   uint64_t tmp = -1;
   int ret;
 
@@ -492,7 +520,9 @@ int onewire_triplet(FAR struct onewire_master_s *master,
 int onewire_search(FAR struct onewire_master_s *master,
                    int family,
                    bool alarmonly,
-                   CODE void (*cb_search)(int family, uint64_t romcode, FAR void *arg),
+                   CODE void (*cb_search)(int family,
+                                          uint64_t romcode,
+                                          FAR void *arg),
                    FAR void *arg)
 {
   FAR struct onewire_dev_s *dev = master->dev;
@@ -704,7 +734,8 @@ FAR struct onewire_master_s *
   DEBUGASSERT(dev != NULL);
   DEBUGASSERT(maxslaves > 0);
 
-  master = (FAR struct onewire_master_s *)kmm_malloc(sizeof(struct onewire_master_s));
+  master = (FAR struct onewire_master_s *)
+    kmm_malloc(sizeof(struct onewire_master_s));
   if (master == NULL)
     {
       i2cerr("ERROR: Failed to allocate\n");
diff --git a/drivers/1wire/1wire_internal.h b/drivers/1wire/1wire_internal.h
index 62f8082ceb..63668e5221 100644
--- a/drivers/1wire/1wire_internal.h
+++ b/drivers/1wire/1wire_internal.h
@@ -92,7 +92,7 @@ bool onewire_check_crc16(FAR const uint8_t *input, uint16_t len,
 
 /* Rest are from 1wire.c */
 
-void onewire_sem_wait(FAR struct onewire_master_s *master);
+int  onewire_sem_wait(FAR struct onewire_master_s *master);
 void onewire_sem_post(FAR struct onewire_master_s *master);
 
 int onewire_addslave(FAR struct onewire_master_s *master,
@@ -163,7 +163,9 @@ int onewire_triplet(FAR struct onewire_master_s *master,
 int onewire_search(FAR struct onewire_master_s *master,
                    int family,
                    bool alarmonly,
-                   CODE void (*cb_search)(int family, uint64_t romcode, FAR void *arg),
+                   CODE void (*cb_search)(int family,
+                                          uint64_t romcode,
+                                          FAR void *arg),
                    FAR  void *arg);
 
 /****************************************************************************
diff --git a/drivers/1wire/ds28e17.c b/drivers/1wire/ds28e17.c
index b183e22287..8e92ad3787 100644
--- a/drivers/1wire/ds28e17.c
+++ b/drivers/1wire/ds28e17.c
@@ -160,7 +160,7 @@ static const struct i2c_ops_s ds_i2c_ops =
  *
  ****************************************************************************/
 
-static inline void ds_i2c_sem_wait(FAR struct i2c_master_s *i2cdev)
+static inline int ds_i2c_sem_wait(FAR struct i2c_master_s *i2cdev)
 {
   FAR struct ds_i2c_inst_s *inst = (FAR struct ds_i2c_inst_s *)i2cdev;
   FAR struct onewire_master_s *master = inst->master;
@@ -205,11 +205,13 @@ static int ds_error(uint8_t buf[])
       i2cerr("I2C device not responding\n");
       return -ENXIO;
     }
+
   if (buf[0] & DS_STATUS_START)
     {
       i2cerr("I2C status start\n");
       return -EAGAIN;
     }
+
   if (buf[0] != 0 || buf[1] != 0)
     {
       i2cerr("I2C IO error\n");
@@ -286,7 +288,8 @@ static int ds_busywait(FAR struct ds_i2c_inst_s *inst, size_t length)
 
          up_udelay(delay);
         }
-    } while (retries-- > 0);
+    }
+  while (retries-- > 0);
 
   i2cwarn("busywait timeout\n");
   return -ETIMEDOUT;
@@ -461,7 +464,8 @@ static int ds_i2c_write(FAR struct ds_i2c_inst_s *inst, uint16_t i2c_addr,
  *
  ****************************************************************************/
 
-static int ds_i2c_write_read(FAR struct ds_i2c_inst_s *inst, uint16_t i2c_addr,
+static int ds_i2c_write_read(FAR struct ds_i2c_inst_s *inst,
+                             uint16_t i2c_addr,
                              FAR const uint8_t *wbuffer, ssize_t wlength,
                              FAR uint8_t *rbuffer, ssize_t rlength)
 {
@@ -552,7 +556,8 @@ static int ds_i2c_write_read(FAR struct ds_i2c_inst_s *inst, uint16_t i2c_addr,
   return ONEWIRE_READ(master->dev, rbuffer, rlength);
 }
 
-static int ds_i2c_setfrequency(FAR struct ds_i2c_inst_s *inst, uint32_t frequency)
+static int ds_i2c_setfrequency(FAR struct ds_i2c_inst_s *inst,
+                               uint32_t frequency)
 {
   FAR struct onewire_master_s *master = inst->master;
   uint8_t buf[2];
@@ -645,15 +650,15 @@ static int ds_i2c_process(FAR struct i2c_master_s *i2cdev,
        * the common case of write followed by read to a same address.
        */
 
-      if (i < count - 1 && msgs[i].addr == msgs[i+1].addr &&
+      if (i < count - 1 && msgs[i].addr == msgs[i + 1].addr &&
           (msgs[i].flags & I2C_M_READ) == 0 &&
-          (msgs[i+1].flags & I2C_M_READ))
+          (msgs[i + 1].flags & I2C_M_READ))
         {
           /* Write-read combined transfer. */
 
           ret = ds_i2c_write_read(inst, msgs[i].addr,
                                   msgs[i].buffer, msgs[i].length,
-                                  msgs[i+1].buffer, msgs[i+1].length);
+                                  msgs[i + 1].buffer, msgs[i + 1].length);
           if (ret < 0)
             {
               i = ret;
@@ -668,7 +673,8 @@ static int ds_i2c_process(FAR struct i2c_master_s *i2cdev,
         {
           /* Read transfer. */
 
-          ret = ds_i2c_read(inst, msgs[i].addr, msgs[i].buffer, msgs[i].length);
+          ret = ds_i2c_read(inst, msgs[i].addr, msgs[i].buffer,
+                            msgs[i].length);
           if (ret < 0)
             {
               i = ret;
@@ -681,8 +687,8 @@ static int ds_i2c_process(FAR struct i2c_master_s *i2cdev,
         {
           /* Write transfer. Stop condition only for last transfer. */
 
-          ret = ds_i2c_write(inst, msgs[i].addr, msgs[i].buffer, msgs[i].length,
-                             i == (count-1));
+          ret = ds_i2c_write(inst, msgs[i].addr, msgs[i].buffer,
+                             msgs[i].length, i == (count - 1));
           if (ret < 0)
             {
               i = ret;
@@ -696,8 +702,9 @@ static int ds_i2c_process(FAR struct i2c_master_s *i2cdev,
 
       if (i < count)
         {
-          /* Yes. Resume to same DS28E17. */
-          /* Oddness: Skip-ROM does not set RS-bit needed by resume. */
+          /* Yes. Resume to same DS28E17.
+           * Oddness: Skip-ROM does not set RS-bit needed by resume.
+           */
 
           if (master->nslaves > 1)
             {
@@ -707,6 +714,7 @@ static int ds_i2c_process(FAR struct i2c_master_s *i2cdev,
             {
               ret = onewire_reset_select(&inst->slave);
             }
+
           if (ret < 0)
             {
               i = ret;
@@ -734,7 +742,12 @@ static int ds_i2c_reset(FAR struct i2c_master_s *i2cdev)
   FAR struct onewire_master_s *master = inst->master;
   int ret;
 
-  ds_i2c_sem_wait(i2cdev);
+  ret = ds_i2c_sem_wait(i2cdev);
+  if (ret < 0)
+    {
+      return ret;
+    }
+
   ret = ONEWIRE_RESET(master->dev);
   ds_i2c_sem_post(i2cdev);
 
@@ -756,7 +769,12 @@ static int ds_i2c_transfer(FAR struct i2c_master_s *i2cdev,
 {
   int ret;
 
-  ds_i2c_sem_wait(i2cdev);
+  ret = ds_i2c_sem_wait(i2cdev);
+  if (ret < 0)
+    {
+      return ret;
+    }
+
   ret = ds_i2c_process(i2cdev, msgs, count);
   ds_i2c_sem_post(i2cdev);
 
@@ -773,8 +791,16 @@ static int ds_i2c_transfer(FAR struct i2c_master_s *i2cdev,
 static int ds28e17_selftest(FAR struct ds_i2c_inst_s *inst)
 {
   FAR struct onewire_master_s *master = inst->master;
-  uint8_t txbuf[] = { ONEWIRE_CMD_READ_ROM };
-  uint8_t rxbuf[8] = { 0 };
+  uint8_t txbuf[] =
+  {
+    ONEWIRE_CMD_READ_ROM
+  };
+
+  uint8_t rxbuf[8] =
+  {
+    0
+  };
+
   uint64_t rom;
   uint8_t crc;
   int ret;
@@ -843,7 +869,9 @@ static int ds28e17_selftest(FAR struct ds_i2c_inst_s *inst)
  ****************************************************************************/
 
 int ds28e17_search(FAR struct ds28e17_dev_s *priv,
-                   void (*cb_search)(int family, uint64_t romcode, void *arg),
+                   void (*cb_search)(int family,
+                                     uint64_t romcode,
+                                     void *arg),
                    void *arg)
 {
   FAR struct onewire_master_s *master = (FAR struct onewire_master_s *)priv;
@@ -851,7 +879,12 @@ int ds28e17_search(FAR struct ds28e17_dev_s *priv,
 
   DEBUGASSERT(master != NULL && cb_search != NULL);
 
-  onewire_sem_wait(master);
+  ret = onewire_sem_wait(master);
+  if (ret < 0)
+    {
+      return ret;
+    }
+
   ret = onewire_search(master, DS_FAMILY, false, cb_search, arg);
   onewire_sem_post(master);
 
@@ -881,6 +914,7 @@ FAR struct i2c_master_s *
 {
   FAR struct ds_i2c_inst_s *inst;  /* device, single instance */
   FAR struct onewire_master_s *master = (FAR struct onewire_master_s *)priv;
+  int ret;
 
   DEBUGASSERT(master != NULL);
 
@@ -903,7 +937,13 @@ FAR struct i2c_master_s *
 
   /* We need a recursive lock as this may be called from a search callback. */
 
-  onewire_sem_wait(master);
+  ret = onewire_sem_wait(master);
+  if (ret < 0)
+    {
+      kmm_free(inst);
+      i2cerr("ERROR: Failed to acquire lock\n");
+      return NULL;
+    }
 
   if (onewire_addslave(master, &inst->slave) < 0)
     {
@@ -953,7 +993,11 @@ int ds28e17_lower_half_unregister(FAR struct ds28e17_dev_s *priv,
   FAR struct onewire_master_s *master = inst->master;
   int ret;
 
-  onewire_sem_wait(master);
+  ret = onewire_sem_wait(master);
+  if (ret < 0)
+    {
+      return ret;
+    }
 
   ret = onewire_removeslave(master, &inst->slave);
   if (ret < 0)
diff --git a/drivers/bch/bch.h b/drivers/bch/bch.h
index b1c5920c57..f6f41346ae 100644
--- a/drivers/bch/bch.h
+++ b/drivers/bch/bch.h
@@ -97,7 +97,7 @@ EXTERN const struct file_operations bch_fops;
  * Public Function Prototypes
  ****************************************************************************/
 
-EXTERN void bchlib_semtake(FAR struct bchlib_s *bch);
+EXTERN int  bchlib_semtake(FAR struct bchlib_s *bch);
 EXTERN int  bchlib_flushsector(FAR struct bchlib_s *bch);
 EXTERN int  bchlib_readsector(FAR struct bchlib_s *bch, size_t sector);
 
diff --git a/drivers/bch/bchdev_driver.c b/drivers/bch/bchdev_driver.c
index 6a2afc5ae4..8d10cd80f4 100644
--- a/drivers/bch/bchdev_driver.c
+++ b/drivers/bch/bchdev_driver.c
@@ -140,7 +140,12 @@ static int bch_open(FAR struct file *filep)
 
   /* Increment the reference count */
 
-  bchlib_semtake(bch);
+  ret = bchlib_semtake(bch);
+  if (ret < 0)
+    {
+      return ret;
+    }
+
   if (bch->refs == MAX_OPENCNT)
     {
       ret = -EMFILE;
@@ -170,9 +175,16 @@ static int bch_close(FAR struct file *filep)
   DEBUGASSERT(inode && inode->i_private);
   bch = (FAR struct bchlib_s *)inode->i_private;
 
+  /* Get exclusive access */
+
+  ret = bchlib_semtake(bch);
+  if (ret < 0)
+    {
+      return ret;
+    }
+
   /* Flush any dirty pages remaining in the cache */
 
-  bchlib_semtake(bch);
   bchlib_flushsector(bch);
 
   /* Decrement the reference count (I don't use bchlib_decref() because I
@@ -231,7 +243,11 @@ static off_t bch_seek(FAR struct file *filep, off_t offset, int whence)
   DEBUGASSERT(inode && inode->i_private);
 
   bch = (FAR struct bchlib_s *)inode->i_private;
-  bchlib_semtake(bch);
+  ret = bchlib_semtake(bch);
+  if (ret < 0)
+    {
+      return (off_t)ret;
+    }
 
   /* Determine the new, requested file position */
 
@@ -298,7 +314,12 @@ static ssize_t bch_read(FAR struct file *filep, FAR char *buffer, size_t len)
   DEBUGASSERT(inode && inode->i_private);
   bch = (FAR struct bchlib_s *)inode->i_private;
 
-  bchlib_semtake(bch);
+  ret = bchlib_semtake(bch);
+  if (ret < 0)
+    {
+      return (ssize_t)ret;
+    }
+
   ret = bchlib_read(bch, buffer, filep->f_pos, len);
   if (ret > 0)
     {
@@ -325,7 +346,12 @@ static ssize_t bch_write(FAR struct file *filep, FAR const char *buffer,
 
   if (!bch->readonly)
     {
-      bchlib_semtake(bch);
+      ret = bchlib_semtake(bch);
+      if (ret < 0)
+        {
+          return (ssize_t)ret;
+        }
+
       ret = bchlib_write(bch, buffer, filep->f_pos, len);
       if (ret > 0)
         {
@@ -366,7 +392,12 @@ static int bch_ioctl(FAR struct file *filep, int cmd, unsigned long arg)
           FAR struct bchlib_s **bchr =
             (FAR struct bchlib_s **)((uintptr_t)arg);
 
-          bchlib_semtake(bch);
+          ret = bchlib_semtake(bch);
+          if (ret < 0)
+            {
+              return ret;
+            }
+
           if (!bchr || bch->refs == MAX_OPENCNT)
             {
               ret   = -EINVAL;
@@ -454,7 +485,11 @@ static int bch_unlink(FAR struct inode *inode)
 
   /* Get exclusive access to the BCH device */
 
-  bchlib_semtake(bch);
+  ret = bchlib_semtake(bch);
+  if (ret < 0)
+    {
+      return ret;
+    }
 
   /* Indicate that the driver has been unlinked */
 
diff --git a/drivers/bch/bchlib_sem.c b/drivers/bch/bchlib_sem.c
index 1495a935fd..999a963186 100644
--- a/drivers/bch/bchlib_sem.c
+++ b/drivers/bch/bchlib_sem.c
@@ -53,7 +53,7 @@
  * Name: bch_semtake
  ****************************************************************************/
 
-void bchlib_semtake(FAR struct bchlib_s *bch)
+int bchlib_semtake(FAR struct bchlib_s *bch)
 {
-  nxsem_wait_uninterruptible(&bch->sem);
+  return nxsem_wait(&bch->sem);
 }
diff --git a/drivers/can/mcp2515.c b/drivers/can/mcp2515.c
index d42335ae10..940725a6ef 100644
--- a/drivers/can/mcp2515.c
+++ b/drivers/can/mcp2515.c
@@ -211,25 +211,25 @@ enum can_state_s
 struct mcp2515_can_s
 {
   struct mcp2515_config_s *config; /* The constant configuration */
-  uint8_t state;            /* See enum can_state_s */
-  uint8_t nalloc;           /* Number of allocated filters */
-  sem_t locksem;            /* Enforces mutually exclusive access */
-  sem_t txfsem;             /* Used to wait for TX FIFO availability */
-  uint32_t btp;             /* Current bit timing */
-  uint8_t rxints;          /* Configured RX interrupts */
-  uint8_t txints;          /* Configured TX interrupts */
+  uint8_t state;                   /* See enum can_state_s */
+  uint8_t nalloc;                  /* Number of allocated filters */
+  sem_t locksem;                   /* Enforces mutually exclusive access */
+  sem_t txfsem;                    /* Used to wait for TX FIFO availability */
+  uint32_t btp;                    /* Current bit timing */
+  uint8_t rxints;                  /* Configured RX interrupts */
+  uint8_t txints;                  /* Configured TX interrupts */
 #ifdef CONFIG_CAN_ERRORS
-  uint32_t olderrors;       /* Used to detect the changes in error states */
+  uint32_t olderrors;              /* Used to detect the changes in error states */
 #endif
-  uint8_t filters;          /* Standard/Extende filter bit allocator. */
-  uint8_t txbuffers;        /* TX Buffers bit allocator. */
+  uint8_t filters;                 /* Standard/Extende filter bit allocator. */
+  uint8_t txbuffers;               /* TX Buffers bit allocator. */
 
   FAR uint8_t *spi_txbuf;
   FAR uint8_t *spi_rxbuf;
 #ifdef CONFIG_MCP2515_REGDEBUG
-  uintptr_t regaddr;        /* Last register address read */
-  uint32_t regval;          /* Last value read from the register */
-  unsigned int count;       /* Number of times that the value was read */
+  uintptr_t regaddr;               /* Last register address read */
+  uint32_t regval;                 /* Last value read from the register */
+  unsigned int count;              /* Number of times that the value was read */
 #endif
 };
 
@@ -241,10 +241,11 @@ struct mcp2515_can_s
 
 static void mcp2515_readregs(FAR struct mcp2515_can_s *priv, uint8_t regaddr,
               FAR uint8_t *buffer, uint8_t len);
-static void mcp2515_writeregs(FAR struct mcp2515_can_s *priv, uint8_t regaddr,
+static void mcp2515_writeregs(FAR struct mcp2515_can_s *priv,
+              uint8_t regaddr,
               FAR const uint8_t *buffer, uint8_t len);
-static void mcp2515_modifyreg(FAR struct mcp2515_can_s *priv, uint8_t regaddr,
-              uint8_t mask, uint8_t value);
+static void mcp2515_modifyreg(FAR struct mcp2515_can_s *priv,
+              uint8_t regaddr, uint8_t mask, uint8_t value);
 #ifdef CONFIG_MCP2515_REGDEBUG
 static void mcp2515_dumpregs(FAR struct mcp2515_can_s *priv,
               FAR const char *msg);
@@ -254,7 +255,7 @@ static void mcp2515_dumpregs(FAR struct mcp2515_can_s *priv,
 
 /* Semaphore helpers */
 
-static void mcp2515_dev_lock(FAR struct mcp2515_can_s *priv);
+static int mcp2515_dev_lock(FAR struct mcp2515_can_s *priv);
 #define mcp2515_dev_unlock(priv) nxsem_post(&priv->locksem)
 
 /* MCP2515 helpers */
@@ -427,7 +428,8 @@ static void mcp2515_transfer(FAR struct mcp2515_can_s *priv, uint8_t len)
  *
  ****************************************************************************/
 
-static void mcp2515_writeregs(FAR struct mcp2515_can_s *priv, uint8_t regaddr,
+static void mcp2515_writeregs(FAR struct mcp2515_can_s *priv,
+                              uint8_t regaddr,
                               FAR const uint8_t *buffer, uint8_t len)
 {
   FAR struct mcp2515_config_s *config = priv->config;
@@ -480,8 +482,8 @@ static void mcp2515_writeregs(FAR struct mcp2515_can_s *priv, uint8_t regaddr,
  *
  ****************************************************************************/
 
-static void mcp2515_modifyreg(FAR struct mcp2515_can_s *priv, uint8_t regaddr,
-                              uint8_t mask, uint8_t value)
+static void mcp2515_modifyreg(FAR struct mcp2515_can_s *priv,
+                              uint8_t regaddr, uint8_t mask, uint8_t value)
 {
   FAR struct mcp2515_config_s *config = priv->config;
   uint8_t wr[4] =
@@ -543,9 +545,9 @@ static void mcp2515_dumpregs(FAR struct mcp2515_can_s *priv,
  *
  ****************************************************************************/
 
-static void mcp2515_dev_lock(FAR struct mcp2515_can_s *priv)
+static int mcp2515_dev_lock(FAR struct mcp2515_can_s *priv)
 {
-  nxsem_wait_uninterruptible(&priv->locksem);
+  return nxsem_wait(&priv->locksem);
 }
 
 /****************************************************************************
@@ -573,13 +575,18 @@ static int mcp2515_add_extfilter(FAR struct mcp2515_can_s *priv,
   uint8_t offset;
   uint8_t mode = CAN_FILTER_MASK;
   int ndx;
+  int ret;
 
   DEBUGASSERT(priv != NULL && priv->config != NULL);
   config = priv->config;
 
   /* Get exclusive excess to the MCP2515 hardware */
 
-  mcp2515_dev_lock(priv);
+  ret = mcp2515_dev_lock(priv);
+  if (ret < 0)
+    {
+      return ret;
+    }
 
   /* Find an unused standard filter */
 
@@ -684,7 +691,8 @@ static int mcp2515_add_extfilter(FAR struct mcp2515_can_s *priv,
               /* STD0 - STD2 */
 
               regval = (regval) |
-                       (uint8_t)(((extconfig->xf_id1 & 0x1c0000) >> 16) << 3);
+                       (uint8_t)(((extconfig->xf_id1 &
+                                   0x1c0000) >> 16) << 3);
               mcp2515_writeregs(priv, MCP2515_RXF0SIDL + offset +
                                 ((priv->nalloc - 1) * 4), &regval, 1);
 
@@ -714,7 +722,8 @@ static int mcp2515_add_extfilter(FAR struct mcp2515_can_s *priv,
               /* STD0 - STD2 */
 
               regval = (regval) |
-                       (uint8_t)(((extconfig->xf_id2 & 0x1c0000) >> 16) << 3);
+                       (uint8_t)(((extconfig->xf_id2 &
+                                   0x1c0000) >> 16) << 3);
               mcp2515_writeregs(priv, MCP2515_RXM0SIDL + offset, &regval, 1);
 
               /* STD3 - STD10 */
@@ -801,6 +810,7 @@ static int mcp2515_del_extfilter(FAR struct mcp2515_can_s *priv, int ndx)
   FAR struct mcp2515_config_s *config;
   uint8_t regval;
   uint8_t offset;
+  int ret;
 
   DEBUGASSERT(priv != NULL && priv->config != NULL);
   config = priv->config;
@@ -818,7 +828,11 @@ static int mcp2515_del_extfilter(FAR struct mcp2515_can_s *priv, int ndx)
 
   /* Get exclusive excess to the MCP2515 hardware */
 
-  mcp2515_dev_lock(priv);
+  ret = mcp2515_dev_lock(priv);
+  if (ret < 0)
+    {
+      return ret;
+    }
 
   /* Check if this filter is really assigned */
 
@@ -902,13 +916,18 @@ static int mcp2515_add_stdfilter(FAR struct mcp2515_can_s *priv,
   uint8_t offset;
   uint8_t mode = CAN_FILTER_MASK;
   int ndx;
+  int ret;
 
   DEBUGASSERT(priv != NULL && priv->config != NULL);
   config = priv->config;
 
   /* Get exclusive excess to the MCP2515 hardware */
 
-  mcp2515_dev_lock(priv);
+  ret = mcp2515_dev_lock(priv);
+  if (ret < 0)
+    {
+      return ret;
+    }
 
   /* Find an unused standard filter */
 
@@ -1074,6 +1093,7 @@ static int mcp2515_del_stdfilter(FAR struct mcp2515_can_s *priv, int ndx)
   FAR struct mcp2515_config_s *config;
   uint8_t regval;
   uint8_t offset;
+  int ret;
 
   DEBUGASSERT(priv != NULL && priv->config != NULL);
   config = priv->config;
@@ -1091,7 +1111,11 @@ static int mcp2515_del_stdfilter(FAR struct mcp2515_can_s *priv, int ndx)
 
   /* Get exclusive excess to the MCP2515 hardware */
 
-  mcp2515_dev_lock(priv);
+  ret = mcp2515_dev_lock(priv);
+  if (ret < 0)
+    {
+      return ret;
+    }
 
   /* Check if this filter is really assigned */
 
@@ -1166,6 +1190,7 @@ static int mcp2515_del_stdfilter(FAR struct mcp2515_can_s *priv, int ndx)
 static void mcp2515_reset_lowlevel(FAR struct mcp2515_can_s *priv)
 {
   FAR struct mcp2515_config_s *config;
+  int ret;
 
   DEBUGASSERT(priv);
   config = priv->config;
@@ -1175,7 +1200,11 @@ static void mcp2515_reset_lowlevel(FAR struct mcp2515_can_s *priv)
 
   /* Get exclusive access to the MCP2515 peripheral */
 
-  mcp2515_dev_lock(priv);
+  ret = mcp2515_dev_lock(priv);
+  if (ret < 0)
+    {
+      return;
+    }
 
   /* Send SPI reset command to MCP2515 */
 
@@ -1263,7 +1292,11 @@ static int mcp2515_setup(FAR struct can_dev_s *dev)
 
   /* Get exclusive access to the MCP2515 peripheral */
 
-  mcp2515_dev_lock(priv);
+  ret = mcp2515_dev_lock(priv);
+  if (ret < 0)
+    {
+      return ret;
+    }
 
   /* MCP2515 hardware initialization */
 
@@ -1521,15 +1554,14 @@ static int mcp2515_ioctl(FAR struct can_dev_s *dev, int cmd,
            * PHSEG1 == PHSEG2 (PHSEG2 = TSEG2)
            *
            * See more at:
+           *  http://www.analog.com/en/analog-dialogue/articles/configure-can-bit-timing.html
            *
-           * http://www.analog.com/en/analog-dialogue/articles/configure-can-bit-timing.html
            */
 
           phseg1 = tseg2;
           prseg  = tseg1 - phseg1;
 
-          brp = (uint32_t)
-            (((float) MCP2515_CANCLK_FREQUENCY /
+          brp = (uint32_t)(((float) MCP2515_CANCLK_FREQUENCY /
              ((float)(tseg1 + tseg2 + 1) * (float)(2 * bt->bt_baud))) - 1);
 
           /* Save the value of the new bit timing register */
@@ -1716,6 +1748,7 @@ static int mcp2515_send(FAR struct can_dev_s *dev, FAR struct can_msg_s *msg)
   uint8_t regval;
   uint8_t txbuf;
   unsigned int nbytes;
+  int ret;
 
   DEBUGASSERT(dev);
   priv = dev->cd_priv;
@@ -1729,11 +1762,21 @@ static int mcp2515_send(FAR struct can_dev_s *dev, FAR struct can_msg_s *msg)
 
   /* Get exclusive access to the MCP2515 peripheral */
 
-  mcp2515_dev_lock(priv);
+  ret = mcp2515_dev_lock(priv);
+  if (ret < 0)
+    {
+      return ret;
+    }
 
   /* Acquire buffer */
 
-  nxsem_wait(&priv->txfsem);
+  ret = nxsem_wait(&priv->txfsem);
+  if (ret < 0)
+    {
+      mcp2515_dev_unlock(priv);
+      return ret;
+    }
+
   DEBUGASSERT(priv->txbuffers != 0);
 
   txbuf = ffs(priv->txbuffers) - 1;
@@ -2485,7 +2528,8 @@ FAR struct mcp2515_can_s *
 
   caninfo("Starting mcp2515_instantiate()!\n");
 
-  priv = (FAR struct mcp2515_can_s *)kmm_malloc(sizeof(struct mcp2515_can_s));
+  priv = (FAR struct mcp2515_can_s *)
+    kmm_malloc(sizeof(struct mcp2515_can_s));
   if (priv == NULL)
     {
       canerr("ERROR: Failed to allocate instance of mcp2515_can_s!\n");
@@ -2553,7 +2597,8 @@ FAR struct mcp2515_can_s *
  *
  ****************************************************************************/
 
-FAR struct can_dev_s *mcp2515_initialize(FAR struct mcp2515_can_s *mcp2515can)
+FAR struct can_dev_s *mcp2515_initialize(
+    FAR struct mcp2515_can_s *mcp2515can)
 {
   FAR struct can_dev_s *dev;
 
diff --git a/drivers/mmcsd/mmcsd_sdio.c b/drivers/mmcsd/mmcsd_sdio.c
index c34aedd6f4..3504316659 100644
--- a/drivers/mmcsd/mmcsd_sdio.c
+++ b/drivers/mmcsd/mmcsd_sdio.c
@@ -142,7 +142,7 @@ struct mmcsd_state_s
 
 /* Misc Helpers *************************************************************/
 
-static void    mmcsd_takesem(FAR struct mmcsd_state_s *priv);
+static int    mmcsd_takesem(FAR struct mmcsd_state_s *priv);
 
 #ifndef CONFIG_SDIO_MUXBUS
 #  define mmcsd_givesem(p) nxsem_post(&priv->sem);
@@ -256,13 +256,19 @@ static const struct block_operations g_bops =
  * Misc Helpers
  ****************************************************************************/
 
-static void mmcsd_takesem(FAR struct mmcsd_state_s *priv)
+static int mmcsd_takesem(FAR struct mmcsd_state_s *priv)
 {
+  int ret;
+
   /* Take the semaphore, giving exclusive access to the driver (perhaps
    * waiting)
    */
 
-  nxsem_wait_uninterruptible(&priv->sem);
+  ret = nxsem_wait_uninterruptible(&priv->sem);
+  if (ret < 0)
+    {
+      return ret;
+    }
 
   /* Lock the bus if mutually exclusive access to the SDIO bus is required
    * on this platform.
@@ -271,6 +277,8 @@ static void mmcsd_takesem(FAR struct mmcsd_state_s *priv)
 #ifdef CONFIG_SDIO_MUXBUS
   SDIO_LOCK(priv->dev, TRUE);
 #endif
+
+  return ret;
 }
 
 #ifdef CONFIG_SDIO_MUXBUS
@@ -2144,6 +2152,7 @@ static ssize_t mmcsd_flush(FAR void *dev, FAR const uint8_t *buffer,
 static int mmcsd_open(FAR struct inode *inode)
 {
   FAR struct mmcsd_state_s *priv;
+  int ret;
 
   finfo("Entry\n");
   DEBUGASSERT(inode && inode->i_private);
@@ -2152,7 +2161,13 @@ static int mmcsd_open(FAR struct inode *inode)
   /* Just increment the reference count on the driver */
 
   DEBUGASSERT(priv->crefs < MAX_CREFS);
-  mmcsd_takesem(priv);
+
+  ret = mmcsd_takesem(priv);
+  if (ret < 0)
+    {
+      return ret;
+    }
+
   priv->crefs++;
   mmcsd_givesem(priv);
   return OK;
@@ -2168,6 +2183,7 @@ static int mmcsd_open(FAR struct inode *inode)
 static int mmcsd_close(FAR struct inode *inode)
 {
   FAR struct mmcsd_state_s *priv;
+  int ret;
 
   finfo("Entry\n");
   DEBUGASSERT(inode && inode->i_private);
@@ -2176,7 +2192,12 @@ static int mmcsd_close(FAR struct inode *inode)
   /* Decrement the reference count on the block driver */
 
   DEBUGASSERT(priv->crefs > 0);
-  mmcsd_takesem(priv);
+  ret = mmcsd_takesem(priv);
+  if (ret < 0)
+    {
+      return ret;
+    }
+
   priv->crefs--;
   mmcsd_givesem(priv);
   return OK;
@@ -2208,7 +2229,11 @@ static ssize_t mmcsd_read(FAR struct inode *inode, unsigned char *buffer,
 
   if (nsectors > 0)
     {
-      mmcsd_takesem(priv);
+      ret = mmcsd_takesem(priv);
+      if (ret < 0)
+        {
+          return (ssize_t)ret;
+        }
 
 #if defined(CONFIG_DRVR_READAHEAD)
       /* Get the data from the read-ahead buffer */
@@ -2282,7 +2307,11 @@ static ssize_t mmcsd_write(FAR struct inode *inode,
   finfo("sector: %lu nsectors: %u sectorsize: %u\n",
         (unsigned long)startsector, nsectors, priv->blocksize);
 
-  mmcsd_takesem(priv);
+  ret = mmcsd_takesem(priv);
+  if (ret < 0)
+    {
+      return (ssize_t)ret;
+    }
 
 #if defined(CONFIG_DRVR_WRITEBUFFER)
   /* Write the data to the write buffer */
@@ -2349,7 +2378,12 @@ static int mmcsd_geometry(FAR struct inode *inode, struct geometry *geometry)
       /* Is there a (supported) card inserted in the slot? */
 
       priv = (FAR struct mmcsd_state_s *)inode->i_private;
-      mmcsd_takesem(priv);
+      ret = mmcsd_takesem(priv);
+      if (ret < 0)
+        {
+          return ret;
+        }
+
       if (IS_EMPTY(priv))
         {
           /* No.. return ENODEV */
@@ -2402,7 +2436,12 @@ static int mmcsd_ioctl(FAR struct inode *inode, int cmd, unsigned long arg)
 
   /* Process the IOCTL by command */
 
-  mmcsd_takesem(priv);
+  ret = mmcsd_takesem(priv);
+  if (ret < 0)
+    {
+      return ret;
+    }
+
   switch (cmd)
     {
     case BIOC_PROBE: /* Check for media in the slot */
@@ -2467,13 +2506,19 @@ static int mmcsd_ioctl(FAR struct inode *inode, int cmd, unsigned long arg)
 static void mmcsd_mediachange(FAR void *arg)
 {
   FAR struct mmcsd_state_s *priv = (FAR struct mmcsd_state_s *)arg;
+  int ret;
 
   finfo("arg: %p\n", arg);
   DEBUGASSERT(priv);
 
   /* Is there a card present in the slot? */
 
-  mmcsd_takesem(priv);
+  ret = mmcsd_takesem(priv);
+  if (ret < 0)
+    {
+      return;
+    }
+
   if (SDIO_PRESENT(priv->dev))
     {
       /* No... process the card insertion.  This could cause chaos if we
@@ -3518,7 +3563,11 @@ static int mmcsd_hwinitialize(FAR struct mmcsd_state_s *priv)
 {
   int ret;
 
-  mmcsd_takesem(priv);
+  ret = mmcsd_takesem(priv);
+  if (ret < 0)
+    {
+      return ret;
+    }
 
   /* Get the capabilities of the SDIO driver */
 
diff --git a/drivers/mmcsd/mmcsd_spi.c b/drivers/mmcsd/mmcsd_spi.c
index ce82a86329..44cf2bdcf3 100644
--- a/drivers/mmcsd/mmcsd_spi.c
+++ b/drivers/mmcsd/mmcsd_spi.c
@@ -163,7 +163,7 @@ struct mmcsd_cmdinfo_s
 
 /* Misc *********************************************************************/
 
-static void     mmcsd_semtake(FAR struct mmcsd_slot_s *slot);
+static int      mmcsd_semtake(FAR struct mmcsd_slot_s *slot);
 static void     mmcsd_semgive(FAR struct mmcsd_slot_s *slot);
 
 /* Card SPI interface *******************************************************/
@@ -386,8 +386,20 @@ static const struct mmcsd_cmdinfo_s g_acmd41 =
  * Name: mmcsd_semtake
  ****************************************************************************/
 
-static void mmcsd_semtake(FAR struct mmcsd_slot_s *slot)
+static int mmcsd_semtake(FAR struct mmcsd_slot_s *slot)
 {
+  int ret;
+
+  /* Get exclusive access to the MMC/SD device (possibly unnecessary if
+   * SPI_LOCK is also implemented as a semaphore).
+   */
+
+  ret = nxsem_wait_uninterruptible(&slot->sem);
+  if (ret < 0)
+    {
+      return ret;
+    }
+
   /* Get exclusive access to the SPI bus (if necessary) */
 
   SPI_LOCK(slot->spi, true);
@@ -401,11 +413,7 @@ static void mmcsd_semtake(FAR struct mmcsd_slot_s *slot)
   SPI_HWFEATURES(slot->spi, 0);
   SPI_SETFREQUENCY(slot->spi, slot->spispeed);
 
-  /* Get exclusive access to the MMC/SD device (possibly unnecessary if
-   * SPI_LOCK is also implemented as a semaphore).
-   */
-
-  nxsem_wait_uninterruptible(&slot->sem);
+  return ret;
 }
 
 /****************************************************************************
@@ -414,10 +422,6 @@ static void mmcsd_semtake(FAR struct mmcsd_slot_s *slot)
 
 static void mmcsd_semgive(FAR struct mmcsd_slot_s *slot)
 {
-  /* Relinquish the lock on the MMC/SD device */
-
-  nxsem_post(&slot->sem);
-
   /* Relinquish the lock on the SPI bus */
 
   /* The card may need up to 8 SCLK cycles to sample the CS status
@@ -429,6 +433,10 @@ static void mmcsd_semgive(FAR struct mmcsd_slot_s *slot)
   /* Relinquish exclusive access to the SPI bus */
 
   SPI_LOCK(slot->spi, false);
+
+  /* Relinquish the lock on the MMC/SD device */
+
+  nxsem_post(&slot->sem);
 }
 
 /****************************************************************************
@@ -1105,10 +1113,16 @@ static int mmcsd_open(FAR struct inode *inode)
     }
 #endif
 
+  ret = mmcsd_semtake(slot);
+  if (ret < 0)
+    {
+      return ret;
+    }
+
   /* Verify that an MMC/SD card has been inserted */
 
   ret = -ENODEV;
-  mmcsd_semtake(slot);
+
   if ((SPI_STATUS(spi, SPIDEV_MMCSD(0)) & SPI_STATUS_PRESENT) != 0)
     {
       /* Yes.. a card is present.  Has it been initialized? */
@@ -1164,8 +1178,9 @@ static ssize_t mmcsd_read(FAR struct inode *inode, unsigned char *buffer,
   FAR struct spi_dev_s *spi;
   size_t nbytes;
   off_t  offset;
-  uint8_t  response;
+  uint8_t response;
   int    i;
+  int ret;
 
   finfo("start_sector=%d nsectors=%d\n", start_sector, nsectors);
 
@@ -1229,7 +1244,12 @@ static ssize_t mmcsd_read(FAR struct inode *inode, unsigned char *buffer,
 
   /* Select the slave */
 
-  mmcsd_semtake(slot);
+  ret = mmcsd_semtake(slot);
+  if (ret < 0)
+    {
+      return (ssize_t)ret;
+    }
+
   SPI_SELECT(spi, SPIDEV_MMCSD(0), true);
 
   /* Single or multiple block read? */
@@ -1321,6 +1341,7 @@ static ssize_t mmcsd_write(FAR struct inode *inode,
   off_t  offset;
   uint8_t response;
   int i;
+  int ret;
 
   finfo("start_sector=%d nsectors=%d\n", start_sector, nsectors);
 
@@ -1394,7 +1415,12 @@ static ssize_t mmcsd_write(FAR struct inode *inode,
 
   /* Select the slave */
 
-  mmcsd_semtake(slot);
+  ret = mmcsd_semtake(slot);
+  if (ret < 0)
+    {
+      return (ssize_t)ret;
+    }
+
   SPI_SELECT(spi, SPIDEV_MMCSD(0), true);
 
   /* Single or multiple block transfer? */
@@ -1536,7 +1562,12 @@ static int mmcsd_geometry(FAR struct inode *inode, struct geometry *geometry)
 
   /* Re-sample the CSD */
 
-  mmcsd_semtake(slot);
+  ret = mmcsd_semtake(slot);
+  if (ret < 0)
+    {
+      return ret;
+    }
+
   SPI_SELECT(spi, SPIDEV_MMCSD(0), true);
   ret = mmcsd_getcsd(slot, csd);
   SPI_SELECT(spi, SPIDEV_MMCSD(0), false);
@@ -1901,7 +1932,12 @@ static void mmcsd_mediachanged(void *arg)
 
   /* Save the current slot state and reassess the new state */
 
-  mmcsd_semtake(slot);
+  ret = mmcsd_semtake(slot);
+  if (ret < 0)
+    {
+      return ret;
+    }
+
   oldstate = slot->state;
 
   /* Check if media was removed or inserted */
@@ -2004,7 +2040,11 @@ int mmcsd_spislotinitialize(int minor, int slotno, FAR struct spi_dev_s *spi)
    * configured for the MMC/SD card
    */
 
-  mmcsd_semtake(slot);
+  ret = mmcsd_semtake(slot);
+  if (ret < 0)
+    {
+      return ret;
+    }
 
   /* Initialize for the media in the slot (if any) */