More fixes to problems noted by cppcheck. Some are kind of risky; some are real bugs.

arch/arm/src/c5471/c5471_serial.c

@@ -84,20 +84,20 @@ struct uart_regs_s
 
 struct up_dev_s
 {
-  unsigned int         uartbase;	/* Base address of UART registers */
+  unsigned int         uartbase;    /* Base address of UART registers */
-  unsigned int         baud_base;	/* Base baud for conversions */
+  unsigned int         baud_base;   /* Base baud for conversions */
-  unsigned int         baud;		/* Configured baud */
+  unsigned int         baud;        /* Configured baud */
-  uint8_t              xmit_fifo_size;	/* Size of transmit FIFO */
+  uint8_t              xmit_fifo_size; /* Size of transmit FIFO */
-  uint8_t              irq;			/* IRQ associated with this UART */
+  uint8_t              irq;         /* IRQ associated with this UART */
-  uint8_t              parity;		/* 0=none, 1=odd, 2=even */
+  uint8_t              parity;      /* 0=none, 1=odd, 2=even */
-  uint8_t              bits;		/* Number of bits (7 or 8) */
+  uint8_t              bits;        /* Number of bits (7 or 8) */
 #ifdef CONFIG_UART_HWFLOWCONTROL
-  bool                 flowcontrol;	/* true: Hardware flow control
+  bool                 flowcontrol; /* true: Hardware flow control
-									 * is enabled. */
+                                     * is enabled. */
 #endif
-  bool                 stopbits2;	/* true: Configure with 2
+  bool                 stopbits2;   /* true: Configure with 2
-									 * stop bits instead of 1 */
+                                     * stop bits instead of 1 */
-  struct uart_regs_s   regs;		/* Shadow copy of readonly regs */
+  struct uart_regs_s   regs;        /* Shadow copy of readonly regs */
 };
 
 /****************************************************************************

arch/arm/src/calypso/calypso_serial.c

@@ -94,23 +94,23 @@ struct uart_regs_s
 
 struct up_dev_s
 {
-  unsigned int         uartbase;	/* Base address of UART registers */
+  unsigned int         uartbase;    /* Base address of UART registers */
-  unsigned int         baud_base;	/* Base baud for conversions */
+  unsigned int         baud_base;   /* Base baud for conversions */
-  unsigned int         baud;		/* Configured baud */
+  unsigned int         baud;        /* Configured baud */
-  uint8_t              xmit_fifo_size;	/* Size of transmit FIFO */
+  uint8_t              xmit_fifo_size; /* Size of transmit FIFO */
-  uint8_t              irq;			/* IRQ associated with this UART */
+  uint8_t              irq;         /* IRQ associated with this UART */
-  uint8_t              parity;		/* 0=none, 1=odd, 2=even */
+  uint8_t              parity;      /* 0=none, 1=odd, 2=even */
-  uint8_t              bits;		/* Number of bits (7 or 8) */
+  uint8_t              bits;        /* Number of bits (7 or 8) */
 #ifdef CONFIG_UART_HWFLOWCONTROL
-  bool                 flowcontrol;	/* true: Hardware flow control
+  bool                 flowcontrol; /* true: Hardware flow control
-									 * is enabled. */
+                                     * is enabled. */
 #endif
-  bool                 stopbits2;	/* true: Configure with 2
+  bool                 stopbits2;   /* true: Configure with 2
-									 * stop bits instead of 1 */
+                                     * stop bits instead of 1 */
-  struct uart_regs_s   regs;		/* Shadow copy of readonly regs */
+  struct uart_regs_s   regs;        /* Shadow copy of readonly regs */
 
 #ifdef CONFIG_SERCOMM_CONSOLE
-  bool                 sercomm;		/* Call sercomm in interrupt if true */
+  bool                 sercomm;     /* Call sercomm in interrupt if true */
 #endif
 };
 

arch/arm/src/efm32/efm32_dma.c

@@ -717,7 +717,7 @@ void efm32_dmastop(DMA_HANDLE handle)
   uint32_t regval;
   uint32_t bit;
 
-  DEBUGASSERT(dmach && dmach);
+  DEBUGASSERT(dmach);
   bit = 1 << dmach->chan;
 
   /* Disable the channel */

arch/arm/src/str71x/str71x_serial.c

@@ -631,8 +631,8 @@ static int up_attach(struct uart_dev_s *dev)
        /* Set the uart interrupt priority (the default value is one) */
 
        up_prioritize_irq(priv->irq, CONFIG_UART_PRI);
-    }
 #endif
+    }
 
   return ret;
 }

arch/arm/src/tiva/tiva_ssi.c

@@ -951,7 +951,6 @@ static int ssi_interrupt(int irq, void *context)
 {
   struct tiva_ssidev_s *priv = ssi_mapirq(irq);
   uint32_t regval;
-  int ntxd;
 
   DEBUGASSERT(priv != NULL);
 
@@ -975,7 +974,7 @@ static int ssi_interrupt(int irq, void *context)
 
   /* Handle outgoing Tx FIFO transfers */
 
-  ntxd = ssi_performtx(priv);
+  (void)ssi_performtx(priv);
 
   /* Handle incoming Rx FIFO transfers */
 

arch/avr/src/avr/up_spi.c

@@ -267,6 +267,8 @@ static uint32_t spi_setfrequency(FAR struct spi_dev_s *dev, uint32_t frequency)
           actual = BOARD_CPU_CLOCK / 128;
         }
 
+#warning REVIST: spcr/spsr are never used
+
       /* Save the frequency setting */
 
 #ifndef CONFIG_SPI_OWNBUS
@@ -531,6 +533,8 @@ FAR struct spi_dev_s *up_spiinitialize(int port)
 #ifndef CONFIG_SPI_OWNBUS
   sem_init(&priv->exclsem, 0, 1);
 #endif
+
+  irqrestore(flags);
   return &priv->spidev;
 }
 #endif /* CONFIG_AVR_SPI */

arch/z80/src/ez80/ez80_spi.c

@@ -359,13 +359,12 @@ static void spi_sndblock(FAR struct spi_dev_s *dev, FAR const void *buffer,
                          size_t buflen)
 {
   FAR const uint8_t *ptr = (FAR const uint8_t*)buffer;
-  uint8_t response;
 
   /* Loop while there are bytes remaining to be sent */
 
   while (buflen-- > 0)
     {
-      response = spi_transfer(*ptr++);
+      (void)spi_transfer(*ptr++);
     }
 }
 

arch/z80/src/ez80/ez80_timerisr.c

@@ -76,16 +76,14 @@
 
 int up_timerisr(int irq, chipreg_t *regs)
 {
-  volatile uint8_t reg;
+  /* Read the appropriate timer0 register to clear the interrupt */
-
-  /* Read the appropropriate timer0 registr to clear the interrupt */
 
 #ifdef _EZ80F91
-  reg = inp(EZ80_TMR0_IIR);
+  (void)inp(EZ80_TMR0_IIR);
 #else
   /* _EZ80190, _EZ80L92, _EZ80F92, _EZ80F93 */
 
-  reg = inp(EZ80_TMR0_CTL);
+  (void)inp(EZ80_TMR0_CTL);
 #endif
 
   /* Process timer interrupt */
@@ -113,7 +111,6 @@ int up_timerisr(int irq, chipreg_t *regs)
 void up_timer_initialize(void)
 {
   uint16_t reload;
-  uint8_t  reg;
 
   /* Disable the timer */
 
@@ -149,9 +146,9 @@ void up_timer_initialize(void)
   /* Clear any pending timer interrupts */
 
 #if defined(_EZ80F91)
-  reg = inp(EZ80_TMR0_IIR);
+  (void)inp(EZ80_TMR0_IIR);
 #elif defined(_EZ80L92) || defined(_EZ80F92) ||defined(_EZ80F93)
-  reg = inp(EZ80_TMR0_CTL);
+  (void)inp(EZ80_TMR0_CTL);
 #endif
 
   /* Configure and enable the timer */

arch/z80/src/z180/z180_scc.c

@@ -575,8 +575,6 @@ static bool z180_txempty(struct uart_dev_s *dev)
 
 void up_serialinit(void)
 {
-  uint8_t regval;
-
   /* Make sure that all UART interrupts are disabled */
 #warning "Missing logic"
 

arch/z80/src/z180/z180_timerisr.c

@@ -94,16 +94,14 @@
 
 int up_timerisr(int irq, chipreg_t *regs)
 {
-  volatile uint8_t regval;
-
   /* "When TMDR0 decrements to 0, TIF0 is set to 1. This generates an interrupt
    * request if enabled by TIE0 = 1. TIF0 is reset to 0 when TCR is read and
    * the higher or lower byte of TMDR0 is read."
    */
 
-  regval = inp(Z180_PRT_TCR);
+  (void)inp(Z180_PRT_TCR);
-  regval = inp(Z180_PRT0_DRL);
+  (void)inp(Z180_PRT0_DRL);
-  regval = inp(Z180_PRT0_DRH);
+  (void)inp(Z180_PRT0_DRH);
 
   /* Process timer interrupt */
 

arch/z80/src/z8/z8_lowuart.c

@@ -75,9 +75,12 @@ extern uint32_t get_freq(void);
 
 void up_lowserialinit(void)
 {
+#if defined(CONFIG_UART0_SERIAL_CONSOLE) || \
+   (defined(EZ8_UART1) && defined(CONFIG_UART1_SERIAL_CONSOLE))
   uint32_t freq = get_freq();
   uint16_t brg;
   uint8_t  val;
+#endif
 
 #ifdef CONFIG_UART0_SERIAL_CONSOLE
   /* Set the baudrate */

audio/pcm_decode.c

@@ -442,8 +442,8 @@ static void pcm_subsample_configure(FAR struct pcm_decode_s *priv,
 
   if (priv->subsample == AUDIO_SUBSAMPLE_NONE)
     {
-      /* Ignore request to stop fast forwarding if we are already
+      /* Ignore request to stop fast forwarding if we are already playing
-       * fast forwarding.
+       * normally.
        */
 
       if (subsample != AUDIO_SUBSAMPLE_NONE)
@@ -460,24 +460,11 @@ static void pcm_subsample_configure(FAR struct pcm_decode_s *priv,
         }
     }
 
-  /* 2. Were already fast forwarding and we have been asked to change the
+  /* 2. We were already fast forwarding and we have been asked to return to
-   *    sub-sampling rate.
-   */
-
-  else if (subsample != AUDIO_SUBSAMPLE_NONE)
-    {
-      /* Just save the current subsample setting.  It will take effect
-       * on the next audio buffer that we receive.
-       */
-
-       priv->subsample = subsample;
-    }
-
-  /* 3. We were already fast forwarding and we have been asked to return to
    *    normal play.
    */
 
-  else if (subsample != AUDIO_SUBSAMPLE_NONE)
+  else if (subsample == AUDIO_SUBSAMPLE_NONE)
     {
       audvdbg("Stop sub-sampling\n");
 
@@ -489,6 +476,19 @@ static void pcm_subsample_configure(FAR struct pcm_decode_s *priv,
       priv->skip      = 0;
       priv->subsample = AUDIO_SUBSAMPLE_NONE;
     }
+
+  /* 3. Were already fast forwarding and we have been asked to change the
+   *    sub-sampling rate.
+   */
+
+  else if (priv->subsample != subsample)
+    {
+      /* Just save the new subsample setting.  It will take effect on the
+       * next audio buffer that we receive.
+       */
+
+       priv->subsample = subsample;
+    }
 }
 #endif
 

configs/ea3131/src/up_mem.c

@@ -157,7 +157,6 @@
 
 static void lpc31_sdraminitialize(void)
 {
-  uint32_t tmp;
   uint32_t regval;
 
   /* These run-time calculations can be reduced dramatically if hclk is
@@ -266,7 +265,7 @@ static void lpc31_sdraminitialize(void)
    * 16bit mode
    */
 
-  tmp = getreg32(LPC31_EXTSDRAM0_VSECTION | (0x23 << 13));
+  (void)getreg32(LPC31_EXTSDRAM0_VSECTION | (0x23 << 13));
 
   putreg32((MPMC_DYNCONFIG0_MDSDRAM|MPMC_DYNCONFIG_HP16_32MX16),
            LPC31_MPMC_DYNCONFIG0);

configs/ea3152/src/up_mem.c

@@ -157,7 +157,6 @@
 
 static void lpc31_sdraminitialize(void)
 {
-  uint32_t tmp;
   uint32_t regval;
 
   /* These run-time calculations can be reduced dramatically if hclk is
@@ -266,7 +265,7 @@ static void lpc31_sdraminitialize(void)
    * 16bit mode
    */
 
-  tmp = getreg32(LPC31_EXTSDRAM0_VSECTION | (0x23 << 13));
+  (void)getreg32(LPC31_EXTSDRAM0_VSECTION | (0x23 << 13));
 
   putreg32((MPMC_DYNCONFIG0_MDSDRAM|MPMC_DYNCONFIG_HP16_32MX16),
            LPC31_MPMC_DYNCONFIG0);

configs/mikroe-stm32f4/src/up_clockconfig.c

@@ -146,5 +146,5 @@ void stm32_board_clockconfig(void)
 
   while ((getreg32(STM32_RCC_CFGR) & RCC_CFGR_SWS_MASK) != RCC_CFGR_SWS_PLL)
     ;
-#endif
 }
+#endif

configs/mikroe-stm32f4/src/up_nsh.c

@@ -169,7 +169,11 @@ int nsh_archinitialize(void)
   FAR struct spi_dev_s *spi;
   FAR struct mtd_dev_s *mtd;
 #endif
+#if defined(NSH_HAVEMMCSD) || defined(HAVE_USBHOST) || \
+    defined(HAVE_USBMONITOR) || defined(CONFIG_LCD_MIO283QT2) || \
+    defined(CONFIG_LCD_MIO283QT9A)
   int ret;
+#endif
 
   /* Configure SPI-based devices */
 

configs/mikroe-stm32f4/src/up_touchscreen.c

@@ -435,7 +435,6 @@ static void tc_adc_init(void)
   regval = tc_adc_getreg(STM32_ADC_SQR3_OFFSET) & ADC_SQR3_RESERVED;
   regval |= LCD_YD_CHANNEL;
   tc_adc_putreg(STM32_ADC_SQR3_OFFSET, regval);
-  regval = tc_adc_getreg(STM32_ADC_SQR3_OFFSET);
 
   /* Set the number of conversions = 1 */
 

configs/mx1ads/src/up_boot.c

@@ -101,7 +101,7 @@ void imx_boardinitialize(void)
   imxgpio_configprimary(GPIOA, 21);
   imxgpio_configprimary(GPIOA, 22);
 
-  regval = getreg32(IMX_CS4_VSECTION + 0x0c);
+  (void)getreg32(IMX_CS4_VSECTION + 0x0c);
-  regval = getreg32(IMX_CS4_VSECTION + 0x0c);
+  (void)getreg32(IMX_CS4_VSECTION + 0x0c);
 #endif
 }

configs/olimex-lpc-h3131/src/lpc31_mem.c

@@ -137,7 +137,6 @@ static uint32_t lpc31_ns2clk(uint32_t ns, uint32_t hclk2)
 
 static inline void lpc31_sdraminitialize(void)
 {
-  uint32_t tmp;
   uint32_t regval;
 
   /* These run-time calculations can be reduced dramatically if hclk is
@@ -254,7 +253,7 @@ static inline void lpc31_sdraminitialize(void)
    * 16bit mode
    */
 
-  tmp = getreg32(LPC31_EXTSDRAM0_VSECTION | (0x23 << 12));
+  (void)getreg32(LPC31_EXTSDRAM0_VSECTION | (0x23 << 12));
 
   /* Select normal operating mode */
 

configs/olimex-stm32-h405/src/stm32_nsh.c

@@ -59,6 +59,10 @@
  * Pre-Processor Definitions
  ****************************************************************************/
 
+#if !defined(CONFIG_STM32_CAN1) && !defined(CONFIG_STM32_CAN2)
+#  undef CONFIG_CAN
+#endif
+
 /****************************************************************************
  * Public Functions
  ****************************************************************************/
@@ -84,7 +88,7 @@ int nsh_archinitialize(void)
   int ret;
 #endif
 
-#if defined(CONFIG_CAN) && (defined(CONFIG_STM32_CAN1) || defined(CONFIG_STM32_CAN2))
+#ifdef CONFIG_CAN
   /* Configure on-board CAN if CAN support has been selected. */
 
   ret = stm32_can_initialize();

configs/open1788/src/lpc17_sdraminitialize.c

@@ -109,11 +109,6 @@
 void open1788_sdram_initialize(void)
 {
   uint32_t regval;
-#ifdef CONFIG_LPC17_SDRAM_16BIT
-  volatile uint16_t dummy;
-#else
-  volatile uint32_t dummy;
-#endif
   int i;
 
   /* Reconfigure delays:
@@ -211,9 +206,9 @@ void open1788_sdram_initialize(void)
            LPC17_EMC_DYNAMICCONTROL);
 
 #ifdef CONFIG_LPC17_SDRAM_16BIT
-  dummy = getreg16(SDRAM_BASE | (0x33 << 12));  /* 8 burst, 3 CAS latency */
+  (void)getreg16(SDRAM_BASE | (0x33 << 12));  /* 8 burst, 3 CAS latency */
 #elif defined CONFIG_LPC17_SDRAM_32BIT
-  dummy = getreg32(SDRAM_BASE | (0x32 << 13)); /* 4 burst, 3 CAS latency */
+  (void)getreg32(SDRAM_BASE | (0x32 << 13)); /* 4 burst, 3 CAS latency */
 #endif
 
   /* Issue NORMAL command */

configs/shenzhou/src/up_ili93xx.c

@@ -1197,14 +1197,14 @@ static int stm32_setpower(struct lcd_dev_s *dev, int power)
       else
 #endif
 #ifndef CONFIG_STM32_ILI9320_DISABLE
-      if (priv->type == LCD_TYPE_ILI9300)
+      if (priv->type == LCD_TYPE_ILI9320)
         {
           stm32_writereg(priv, LCD_REG_7, 0x0173);
         }
       else
 #endif
 #ifndef CONFIG_STM32_ILI9321_DISABLE
-      if (priv->type == LCD_TYPE_ILI9300)
+      if (priv->type == LCD_TYPE_ILI9321)
         {
           stm32_writereg(priv, LCD_REG_7, 0x0173);
         }

configs/stm32f4discovery/src/stm32_usb.c

@@ -170,7 +170,10 @@ void stm32_usbinitialize(void)
 int stm32_usbhost_initialize(void)
 {
   int pid;
+#if defined(CONFIG_USBHOST_MSC) || defined(CONFIG_USBHOST_HIDKBD) || \
+    defined(CONFIG_USBHOST_HIDMOUSE)
   int ret;
+#endif
 
   /* First, register all of the class drivers needed to support the drivers
    * that we care about:

configs/vsn/src/sif.c

@@ -577,7 +577,8 @@ int sif_main(int argc, char *argv[])
                 }
                 else if (status != 0) {
                     if (stpage != 0xFFFF) {
-                        printf("Free Range:\t%d\t-\t%d\n", stpage, page-2);
+                        printf("Free Range:\t%lu\t-\t%lu\n",
+                               (unsigned long)stpage, (unsigned long)(page-2));
                         stpage = 0xFFFF;
                     }
                 }
@@ -594,8 +595,8 @@ int sif_main(int argc, char *argv[])
             size_t page = atoi(argv[2]);
             size_t addr = page * up_progmem_pagesize(page);
 
-            printf("Write result: %d (writing to address %xh)\n",
+            printf("Write result: %d (writing to address %lxh)\n",
-                up_progmem_write(addr, "Test", 4), addr);
+                up_progmem_write(addr, "Test", 4), (unsigned long)addr);
             return 0;
         }
         else if (!strcmp(argv[1], "i2c") && argc == 3) {

crypto/crypto.c

@@ -66,21 +66,31 @@
 
 void up_cryptoinitialize(void)
 {
-  int res = OK;
+#if defined(CONFIG_CRYPTO_AES) || defined(CONFIG_CRYPTO_ALGTEST)
+  int res;
 
-#if defined(CONFIG_CRYPTO_AES)
+#ifdef CONFIG_CRYPTO_AES
   res = up_aesinitialize();
   if (res)
-    return res;
+    {
+      return res;
+    }
 #endif
 
-#if defined(CONFIG_CRYPTO_ALGTEST)
+#if CONFIG_CRYPTO_ALGTEST
   res = crypto_test();
   if (res)
-    cryptlldbg("crypto test failed\n");
+    {
+      cryptlldbg("crypto test failed\n");
+    }
   else
-    cryptllvdbg("crypto test OK\n");
+    {
+      cryptllvdbg("crypto test OK\n");
+    }
 #endif
 
   return res;
-}
+#else
+  return OK;
+#endif
+}

drivers/analog/ads1255.c

@@ -168,23 +168,25 @@ static uint8_t getspsreg(uint16_t sps)
 {
   static const unsigned short sps_tab[]=
   {
-    3,7,12,20,27,40,55,80,300,750,1500,3000,5000,10000,20000,65535,
+      3,     7,     12,    20,    27,    40,    55,    80,
+    300,   750,   1500,  3000,  5000, 10000, 20000, 65535,
   };
   static const unsigned char sps_reg[]=
   {
-    0x03,0x13,0x23,0x33,0x43,0x53,0x63,0x72,0x82,0x92,0xa1,0xb0,0xc0,0xd0,0xe0,0xf0,
+    0x03,  0x13,  0x23,  0x33,  0x43,  0x53,  0x63,  0x72,
+    0x82,  0x92,  0xa1,  0xb0,  0xc0,  0xd0,  0xe0,  0xf0,
   };
   int i;
 
-  for (i=0; i<16; i++)
+  for (i = 0; i < 16; i++)
     {
-      if (sps<sps_tab[i])
+      if (sps < sps_tab[i])
         {
-          break;
+          return sps_reg[i];
         }
     }
 
-  return sps_reg[i];
+  return sps_reg[15];
 }
 
 /****************************************************************************

drivers/audio/wm8904.c

@@ -1685,7 +1685,7 @@ static int wm8904_enqueuebuffer(FAR struct audio_lowerhalf_s *dev,
 {
   FAR struct wm8904_dev_s *priv = (FAR struct wm8904_dev_s *)dev;
   struct audio_msg_s  term_msg;
-  int ret = -EAGAIN;
+  int ret;
 
   audvdbg("Enqueueing: apb=%p curbyte=%d nbytes=%d flags=%04x\n",
           apb, apb->curbyte, apb->nbytes, apb->flags);

drivers/input/mxt.c

@@ -750,6 +750,8 @@ static void mxt_button_event(FAR struct mxt_dev_s *priv,
           button = (msg->body[0] & mask) == 0;
 
           /* Now what? */
+
+          UNUSED(button);
         }
     }
 }

drivers/lcd/mio283qt9a.c

@@ -719,11 +719,13 @@ static int mio283qt9a_setcontrast(FAR struct lcd_dev_s *dev, unsigned int contra
 static inline int mio283qt9a_hwinitialize(FAR struct mio283qt9a_dev_s *priv)
 {
   FAR struct mio283qt9a_lcd_s *lcd  = priv->lcd;
-#ifndef CONFIG_LCD_NOGETRUN
+#if !defined(CONFIG_LCD_NOGETRUN) || defined(CONFIG_DEBUG_LCD)
   uint16_t id_a;
   uint16_t id_b;
   uint16_t id_c;
   uint16_t id_d;
+#endif
+#ifdef CONFIG_DEBUG_LCD
   uint16_t id_e;
 #endif
   int ret;
@@ -741,6 +743,8 @@ static inline int mio283qt9a_hwinitialize(FAR struct mio283qt9a_dev_s *priv)
   id_d = lcd->read(lcd);
 
   lcdvdbg("LCD ID: %04x %04x %04x %04x\n", id_a, id_b, id_c, id_d);
+  UNUSED(id_a);
+  UNUSED(id_b);
 
   /* Check if the ID is for the ILI9341 */
 
@@ -773,6 +777,7 @@ static inline int mio283qt9a_hwinitialize(FAR struct mio283qt9a_dev_s *priv)
       mio283qt9a_putreg(lcd, 0x11, 0);      /* Sleep out mode */
       up_mdelay(25);
 
+#ifdef CONFIG_DEBUG_LCD
       /* Read back some info from the panel */
 
       id_a = mio283qt9a_readreg(lcd, 0x04); /* Read display information */
@@ -811,6 +816,7 @@ static inline int mio283qt9a_hwinitialize(FAR struct mio283qt9a_dev_s *priv)
       id_a = mio283qt9a_readreg(lcd, 0x0f);  /* read self diag */
       id_b = lcd->read(lcd);
       lcdvdbg("Self diag %02x, %02x\n", id_a, id_b);
+#endif
       ret = OK;
     }
 #ifndef CONFIG_LCD_NOGETRUN

drivers/mtd/rammtd.c

@@ -453,7 +453,7 @@ FAR struct mtd_dev_s *rammtd_initialize(FAR uint8_t *start, size_t size)
   /* Force the size to be an even number of the erase block size */
 
   nblocks = size / CONFIG_RAMMTD_ERASESIZE;
-  if (nblocks <= 0)
+  if (nblocks < 1)
     {
       fdbg("Need to provide at least one full erase block\n");
       return NULL;

drivers/mtd/smart.c

@@ -836,11 +836,11 @@ static int smart_scan(struct smart_struct_s *dev)
 
               rootdirdev->dev = dev;
               rootdirdev->rootdirnum = x;
-              ret = register_blockdriver(dev->rwbuffer, &g_bops, 0, rootdirdev);
+              (void)register_blockdriver(dev->rwbuffer, &g_bops, 0, rootdirdev);
 
               /* Inode private data is a reference to the SMART device structure */
 
-              ret = register_blockdriver(devname, &g_bops, 0, rootdirdev);
+              (void)register_blockdriver(devname, &g_bops, 0, rootdirdev);
             }
 #endif
         }
@@ -1359,7 +1359,7 @@ static int smart_garbagecollect(struct smart_struct_s *dev)
 
               /* Write the data to the new physical sector location */
 
-              ret = MTD_BWRITE(dev->mtd, newsector * dev->mtdBlksPerSector,
+              (void)MTD_BWRITE(dev->mtd, newsector * dev->mtdBlksPerSector,
                                dev->mtdBlksPerSector, (uint8_t *) dev->rwbuffer);
 
               /* Commit the sector */

drivers/mtd/sst25.c

@@ -714,7 +714,7 @@ static void sst25_wordwrite(struct sst25_dev_s *priv, FAR const uint8_t *buffer,
        * we are finished.
        */
 
-      if (nwords <= 0)
+      if (nwords < 1)
         {
           return;
         }

drivers/net/dm90x0.c

@@ -891,8 +891,6 @@ static void dm9x_receive(struct dm9x_driver_s *dm9x)
 {
   union rx_desc_u rx;
   bool bchecksumready;
-  uint8_t mdrah;
-  uint8_t mdral;
   uint8_t rxbyte;
 
   nvdbg("Packet received\n");
@@ -901,8 +899,8 @@ static void dm9x_receive(struct dm9x_driver_s *dm9x)
     {
       /* Store the value of memory data read address register */
 
-      mdrah = getreg(DM9X_MDRAH);
+      (void)getreg(DM9X_MDRAH);
-      mdral = getreg(DM9X_MDRAL);
+      (void)getreg(DM9X_MDRAL);
 
       getreg(DM9X_MRCMDX);         /* Dummy read */
       rxbyte = (uint8_t)DM9X_DATA; /* Get the most up-to-date data */

drivers/net/e1000.c

@@ -270,7 +270,7 @@ void e1000_turn_off(struct e1000_dev *dev)
 
 void e1000_init(struct e1000_dev *dev)
 {
-  uint32_t rxd_phy;
+  uint32_t rxd_phys;
   uint32_t txd_phys;
   uint32_t kmem_phys;
   uint32_t rx_control;
@@ -570,35 +570,33 @@ static void e1000_receive(struct e1000_dev *e1000)
 #ifdef CONFIG_NET_IPv6
       if (BUF->type == HTONS(ETHTYPE_IP6))
 #else
-        {
+      if (BUF->type == HTONS(ETHTYPE_IP))
-          if (BUF->type == HTONS(ETHTYPE_IP))
 #endif
+        {
+          arp_ipin(&e1000->netdev);
+          devif_input(&e1000->netdev);
+
+          /* If the above function invocation resulted in data that should be
+           * sent out on the network, the field  d_len will set to a value > 0.
+           */
+
+          if (e1000->netdev.d_len > 0)
             {
-              arp_ipin(&e1000->netdev);
+              arp_out(&e1000->netdev);
-              devif_input(&e1000->netdev);
+              e1000_transmit(e1000);
-
-              /* If the above function invocation resulted in data that should be
-               * sent out on the network, the field  d_len will set to a value > 0.
-               */
-
-              if (e1000->netdev.d_len > 0)
-                {
-                  arp_out(&e1000->netdev);
-                  e1000_transmit(e1000);
-                }
             }
-          else if (BUF->type == htons(ETHTYPE_ARP))
+        }
+      else if (BUF->type == htons(ETHTYPE_ARP))
+        {
+          arp_arpin(&e1000->netdev);
+
+          /* If the above function invocation resulted in data that should be
+           * sent out on the network, the field  d_len will set to a value > 0.
+           */
+
+          if (e1000->netdev.d_len > 0)
             {
-              arp_arpin(&e1000->netdev);
+              e1000_transmit(e1000);
-
-              /* If the above function invocation resulted in data that should be
-               * sent out on the network, the field  d_len will set to a value > 0.
-               */
-
-              if (e1000->netdev.d_len > 0)
-                {
-                  e1000_transmit(e1000);
-                }
             }
         }
 

drivers/power/max1704x.c

@@ -271,7 +271,6 @@ static int max1704x_getreg16(FAR struct max1704x_dev_s *priv, uint8_t regaddr,
   /* Return the 16-bit value */
 
   return (uint16_t)buffer[0] << 8 | (uint16_t)buffer[1];
-  return OK;
 }
 
 /****************************************************************************

drivers/power/pm_activity.c

@@ -156,7 +156,7 @@ void pm_activity(int priority)
            * controlled priority.
            */
 
-          (void)pm_update(accum);
+          (void)pm_update(tmp);
         }
 
       irqrestore(flags);

drivers/usbdev/usbmsc_scsi.c

@@ -365,7 +365,7 @@ static void usbmsc_putle32(uint8_t *buf, uint32_t val)
 
 static void usbmsc_scsi_wait(FAR struct usbmsc_dev_s *priv)
 {
-  irqstate_t flags = irqsave();
+  irqstate_t flags;
   int ret;
 
   /* We must hold the SCSI lock to call this function */
@@ -2802,7 +2802,7 @@ int usbmsc_scsi_main(int argc, char *argv[])
 
 void usbmsc_scsi_signal(FAR struct usbmsc_dev_s *priv)
 {
-  irqstate_t flags = irqsave();
+  irqstate_t flags;
 
   /* A flag is used to prevent driving up the semaphore count.  This function
    * is called (primarily) from interrupt level logic so we must disable