diff --git a/ChangeLog b/ChangeLog
index 6fad0d0ba9..bf7e051686 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -3675,3 +3675,9 @@
 	  file paths.
 	* nuttx/arch/arm/src/arm/Toolchain.defs: Add support for more ARM toolchains
 	  (from Mike Smith).
+	* arch/arm/src/stm32/stm32f40xxx_rcc.c:  Enabled FLASH prefetch (from Petteri
+	  Aimonen).
+	* graphics/nxtk/nxtk_filltrapwindow.c:  Correct an offset problem (from
+	  Peterri Aimonen).
+	* graphics/nxglib/nxglib_splitline.c:  Fix error in drawing of near horizontal
+	  lines (from Peterri Aimonen).
diff --git a/arch/arm/src/stm32/chip/stm32_flash.h b/arch/arm/src/stm32/chip/stm32_flash.h
index c2e4409239..d6fcecc114 100644
--- a/arch/arm/src/stm32/chip/stm32_flash.h
+++ b/arch/arm/src/stm32/chip/stm32_flash.h
@@ -110,6 +110,7 @@
 #  define FLASH_ACR_HLFCYA          (1 << 3)                /* FLASH half cycle access */
 #  define FLASH_ACR_PRTFBE          (1 << 4)                /* FLASH prefetch enable */
 #elif defined(CONFIG_STM32_STM32F20XX) || defined(CONFIG_STM32_STM32F40XX)
+#  define FLASH_ACR_PRFTEN          (1 << 8)                /* FLASH prefetch enable */
 #  define FLASH_ACR_ICEN            (1 << 9)                /* Bit 9: Instruction cache enable */
 #  define FLASH_ACR_DCEN            (1 << 10)               /* Bit 10: Data cache enable */
 #  define FLASH_ACR_ICRST           (1 << 11)               /* Bit 11: Instruction cache reset */
diff --git a/arch/arm/src/stm32/stm32_serial.c b/arch/arm/src/stm32/stm32_serial.c
index 6c1861ef8c..c7f97b25ac 100644
--- a/arch/arm/src/stm32/stm32_serial.c
+++ b/arch/arm/src/stm32/stm32_serial.c
@@ -101,11 +101,11 @@
  */
 
 #  if (defined(CONFIG_USART1_RXDMA) && defined(CONFIG_USART1_RS485)) || \
-      (defined(CONFIG_USART2_RXDMA) && defined(CONFIG_USART2_RS485)) ||  \
-      (defined(CONFIG_USART3_RXDMA) && defined(CONFIG_USART3_RS485)) ||  \
-      (defined(CONFIG_UART4_RXDMA) && defined(CONFIG_UART4_RS485)) ||  \
-      (defined(CONFIG_UART5_RXDMA) && defined(CONFIG_UART5_RS485)) ||  \
-      (defined(CONFIG_USART6_RXDMA) && defined(CONFIG_USART6_RS485)) \
+      (defined(CONFIG_USART2_RXDMA) && defined(CONFIG_USART2_RS485)) || \
+      (defined(CONFIG_USART3_RXDMA) && defined(CONFIG_USART3_RS485)) || \
+      (defined(CONFIG_UART4_RXDMA) && defined(CONFIG_UART4_RS485)) || \
+      (defined(CONFIG_UART5_RXDMA) && defined(CONFIG_UART5_RS485)) || \
+      (defined(CONFIG_USART6_RXDMA) && defined(CONFIG_USART6_RS485))
 #    error "RXDMA and RS-485 cannot be enabled at the same time for the same U[S]ART"
 #  endif
 
diff --git a/arch/arm/src/stm32/stm32f40xxx_rcc.c b/arch/arm/src/stm32/stm32f40xxx_rcc.c
index 45980f2889..14ee1e7549 100644
--- a/arch/arm/src/stm32/stm32f40xxx_rcc.c
+++ b/arch/arm/src/stm32/stm32f40xxx_rcc.c
@@ -633,7 +633,7 @@ static void stm32_stdclockconfig(void)
  
       /* Enable FLASH prefetch, instruction cache, data cache, and 5 wait states */
 
-      regval = (FLASH_ACR_LATENCY_5 | FLASH_ACR_ICEN | FLASH_ACR_DCEN);
+      regval = (FLASH_ACR_LATENCY_5 | FLASH_ACR_ICEN | FLASH_ACR_DCEN | FLASH_ACR_PRFTEN);
       putreg32(regval, STM32_FLASH_ACR);
 
       /* Select the main PLL as system clock source */
diff --git a/graphics/nxglib/nxglib_splitline.c b/graphics/nxglib/nxglib_splitline.c
index 84892b67e3..cbf2d5ff37 100644
--- a/graphics/nxglib/nxglib_splitline.c
+++ b/graphics/nxglib/nxglib_splitline.c
@@ -41,6 +41,7 @@
 
 #include <string.h>
 #include <errno.h>
+#include <stdlib.h>
 
 #include <nuttx/nx/nxglib.h>
 
@@ -192,9 +193,11 @@ int nxgl_splitline(FAR struct nxgl_vector_s *vector,
 
   /* The final degenerate case */
 
-  if (linewidth == 1)
+  if (linewidth == 1 &&
+      abs(line.pt2.x - line.pt1.x) < (line.pt2.y - line.pt1.y))
     {
-      /* A line of width 1 is basically a single parallelogram of width 1 */
+      /* A close to vertical line of width 1 is basically
+       * a single parallelogram of width 1 */
 
       traps[1].top.x1 = itob16(line.pt1.x);
       traps[1].top.x2 = traps[1].top.x1;
diff --git a/graphics/nxtk/nxtk_filltrapwindow.c b/graphics/nxtk/nxtk_filltrapwindow.c
index c1032f1e75..55c051ffd7 100644
--- a/graphics/nxtk/nxtk_filltrapwindow.c
+++ b/graphics/nxtk/nxtk_filltrapwindow.c
@@ -94,6 +94,7 @@ int nxtk_filltrapwindow(NXTKWINDOW hfwnd, FAR const struct nxgl_trapezoid_s *tra
 {
   FAR struct nxtk_framedwindow_s *fwnd = (FAR struct nxtk_framedwindow_s *)hfwnd;
   struct nxgl_rect_s relclip;
+  struct nxgl_trapezoid_s reltrap;
 
 #ifdef CONFIG_DEBUG
   if (!hfwnd || !trap || !color)
@@ -103,8 +104,14 @@ int nxtk_filltrapwindow(NXTKWINDOW hfwnd, FAR const struct nxgl_trapezoid_s *tra
     }
 #endif
 
-  /* Perform the fill, clipping to the client window */
+  /* Move the trapezoid from window contents area to window area */
 
+  nxgl_trapoffset(&reltrap, trap,
+                  fwnd->fwrect.pt1.x - fwnd->wnd.bounds.pt1.x,
+                  fwnd->fwrect.pt1.y - fwnd->wnd.bounds.pt1.y);
+  
+  /* Perform the fill, clipping to the client window */
   nxgl_rectoffset(&relclip, &fwnd->fwrect, -fwnd->wnd.bounds.pt1.x, -fwnd->wnd.bounds.pt1.y);
-  return nx_filltrapezoid((NXWINDOW)hfwnd, &relclip, trap, color);
+  
+  return nx_filltrapezoid((NXWINDOW)hfwnd, &relclip, &reltrap, color);
 }