Fix STM32F1 and F3 USB device driver. It was not handling NULL packets correctly and it prevent use of the driver with the CDC/ACM class

4 files changed, 145 insertions, 57 deletions

diff --git a/nuttx/configs/stm32f3discovery/README.txt b/nuttx/configs/stm32f3discovery/README.txt
index 82d5efd1e..12811b8a0 100644
--- a/nuttx/configs/stm32f3discovery/README.txt
+++ b/nuttx/configs/stm32f3discovery/README.txt
@@ -323,7 +323,7 @@ the following settings in the include/board.h file:
 This can be found on the board at:
 
   TX, PA2, Connector P1, pin 14
-  RX, PA3, Connector P1, pin 9
+  RX, PA3, Connector P1, pin 11
 
 FPU
 ===
@@ -726,7 +726,7 @@ Where <subdir> is one of the following:
   nsh:
   ---
     Configures the NuttShell (nsh) located at apps/examples/nsh.  The
-    Configuration enables the serial interfaces on UART2.  Support for
+    Configuration enables the serial interfaces on USART2.  Support for
     builtin applications is enabled, but in the base configuration no
     builtin applications are selected (see NOTES below).
 
@@ -824,41 +824,59 @@ Where <subdir> is one of the following:
        for Windows and builds under Cygwin (or probably MSYS).  That
        can easily be reconfigured, of course.
 
-       CONFIG_HOST_WINDOWS=y                   : Builds under Windows
-       CONFIG_WINDOWS_CYGWIN=y                 : Using Cygwin
-       CONFIG_ARMV7M_TOOLCHAIN_CODESOURCERYW=y : CodeSourcery for Windows
+       Build Setup:
+         CONFIG_HOST_WINDOWS=y                   : Builds under Windows
+         CONFIG_WINDOWS_CYGWIN=y                 : Using Cygwin
 
-    3. This configuration does have UART2 output enabled and set up as
+       System Type:
+         CONFIG_ARMV7M_TOOLCHAIN_CODESOURCERYW=y : CodeSourcery for Windows
+
+    3. This configuration does have USART2 output enabled and set up as
        the system logging device:
 
-       CONFIG_SYSLOG=y                    : Enable output to syslog, not console
-       CONFIG_SYSLOG_CHAR=y               : Use a character device for system logging
-       CONFIG_SYSLOG_DEVPATH="/dev/ttyS0" : UART2 will be /dev/ttyS0
+       Device Drivers -> System Logging Device Options:
+         CONFIG_SYSLOG=y                    : Enable output to syslog, not console
+         CONFIG_SYSLOG_CHAR=y               : Use a character device for system logging
+         CONFIG_SYSLOG_DEVPATH="/dev/ttyS0" : USART2 will be /dev/ttyS0
 
        However, there is nothing to generate SYLOG output in the default
-       configuration so nothing should appear on UART2 unless you enable
+       configuration so nothing should appear on USART2 unless you enable
        some debug output or enable the USB monitor.
 
+       NOTE:  Using the SYSLOG to get debug output has limitations.  Among
+       those are that you cannot get debug output from interrupt handlers.
+       So, in particularly, debug output is not a useful way to debug the
+       USB device controller driver.  Instead, use the USB monitor with
+       USB debug off and USB trance on (see below).
+
     4. Enabling USB monitor SYSLOG output.  If tracing is enabled, the USB
        device will save encoded trace output in in-memory buffer; if the
        USB monitor is enabled, that trace buffer will be periodically
-       emptied and dumped to the system loggin device (UART2 in this
+       emptied and dumped to the system loggin device (USART2 in this
        configuraion):
 
-       CONFIG_USBDEV_TRACE=y                   : Enable USB trace feature
-       CONFIG_USBDEV_TRACE_NRECORDS=128        : Buffer 128 records in memory
-       CONFIG_NSH_USBDEV_TRACE=n               : No builtin tracing from NSH
-       CONFIG_NSH_ARCHINIT=y                   : Automatically start the USB monitor
-       CONFIG_SYSTEM_USBMONITOR=y              : Enable the USB monitor daemon
-       CONFIG_SYSTEM_USBMONITOR_STACKSIZE=2048 : USB monitor daemon stack size
-       CONFIG_SYSTEM_USBMONITOR_PRIORITY=50    : USB monitor daemon priority
-       CONFIG_SYSTEM_USBMONITOR_INTERVAL=2     : Dump trace data every 2 seconds
-
-       CONFIG_SYSTEM_USBMONITOR_TRACEINIT=y    : Enable TRACE output
-       CONFIG_SYSTEM_USBMONITOR_TRACECLASS=y
-       CONFIG_SYSTEM_USBMONITOR_TRACETRANSFERS=y
-       CONFIG_SYSTEM_USBMONITOR_TRACECONTROLLER=y
-       CONFIG_SYSTEM_USBMONITOR_TRACEINTERRUPTS=y
+        Device Drivers -> "USB Device Driver Support:
+          CONFIG_USBDEV_TRACE=y                   : Enable USB trace feature
+          CONFIG_USBDEV_TRACE_NRECORDS=256        : Buffer 128 records in memory
+
+        Application Configuration -> NSH LIbrary:
+          CONFIG_NSH_USBDEV_TRACE=n               : No builtin tracing from NSH
+          CONFIG_NSH_ARCHINIT=y                   : Automatically start the USB monitor
+
+        Application Configuration -> System NSH Add-Ons:
+          CONFIG_SYSTEM_USBMONITOR=y              : Enable the USB monitor daemon
+          CONFIG_SYSTEM_USBMONITOR_STACKSIZE=2048 : USB monitor daemon stack size
+          CONFIG_SYSTEM_USBMONITOR_PRIORITY=50    : USB monitor daemon priority
+          CONFIG_SYSTEM_USBMONITOR_INTERVAL=1     : Dump trace data every second
+          CONFIG_SYSTEM_USBMONITOR_TRACEINIT=y    : Enable TRACE output
+          CONFIG_SYSTEM_USBMONITOR_TRACECLASS=y
+          CONFIG_SYSTEM_USBMONITOR_TRACETRANSFERS=y
+          CONFIG_SYSTEM_USBMONITOR_TRACECONTROLLER=y
+          CONFIG_SYSTEM_USBMONITOR_TRACEINTERRUPTS=y
+
+       NOTE: USB debug output also be enabled in this case.  Both will appear
+       on the serial SYSLOG output.  However, the debug output will be
+       asynchronous with the trace output and, hence, difficult to interpret.
 
     5. The STM32F3Discovery board does not provide circuitry for control of
        the "soft connect" USB pullup.  As a result, the host PC does not know
@@ -868,15 +886,13 @@ Where <subdir> is one of the following:
        1) Start NSH with USB disconnected, then
        2) Connect the USB device to the host.
  
-    5. By default, this project assumes that you are *NOT* using the DFU
-       bootloader.
+    6. Using the Prolifics PL2303 Emulation
 
-    Using the Prolifics PL2303 Emulation
-    ------------------------------------
-    You could also use the non-standard PL2303 serial device instead of
-    the standard CDC/ACM serial device by changing:
+       You could also use the non-standard PL2303 serial device instead of
+       the standard CDC/ACM serial device by changing:
 
-      CONFIG_CDCACM=y               : Disable the CDC/ACM serial device class
-      CONFIG_CDCACM_CONSOLE=y       : The CDC/ACM serial device is NOT the console
-      CONFIG_PL2303=y               : The Prolifics PL2303 emulation is enabled
-      CONFIG_PL2303_CONSOLE=y       : The PL2303 serial device is the console
+       Drivers->USB Device Driver Support
+         CONFIG_CDCACM=y               : Disable the CDC/ACM serial device class
+         CONFIG_CDCACM_CONSOLE=y       : The CDC/ACM serial device is NOT the console
+         CONFIG_PL2303=y               : The Prolifics PL2303 emulation is enabled
+         CONFIG_PL2303_CONSOLE=y       : The PL2303 serial device is the console
diff --git a/nuttx/configs/stm32f3discovery/usbnsh/defconfig b/nuttx/configs/stm32f3discovery/usbnsh/defconfig
index 3f5272231..814fba52b 100644
--- a/nuttx/configs/stm32f3discovery/usbnsh/defconfig
+++ b/nuttx/configs/stm32f3discovery/usbnsh/defconfig
@@ -69,12 +69,14 @@ CONFIG_ARCH="arm"
 # CONFIG_ARCH_CHIP_DM320 is not set
 # CONFIG_ARCH_CHIP_IMX is not set
 # CONFIG_ARCH_CHIP_KINETIS is not set
+# CONFIG_ARCH_CHIP_KL is not set
 # CONFIG_ARCH_CHIP_LM is not set
 # CONFIG_ARCH_CHIP_LPC17XX is not set
 # CONFIG_ARCH_CHIP_LPC214X is not set
 # CONFIG_ARCH_CHIP_LPC2378 is not set
 # CONFIG_ARCH_CHIP_LPC31XX is not set
 # CONFIG_ARCH_CHIP_LPC43XX is not set
+# CONFIG_ARCH_CHIP_NUC1XX is not set
 # CONFIG_ARCH_CHIP_SAM3U is not set
 CONFIG_ARCH_CHIP_STM32=y
 # CONFIG_ARCH_CHIP_STR71X is not set
@@ -87,8 +89,6 @@ CONFIG_ARCH_HAVE_CMNVECTOR=y
 # CONFIG_ARCH_FPU is not set
 CONFIG_ARCH_HAVE_MPU=y
 # CONFIG_ARMV7M_MPU is not set
-CONFIG_BOARD_LOOPSPERMSEC=6522
-# CONFIG_ARCH_CALIBRATION is not set
 
 #
 # ARMV7M Configuration Options
@@ -105,6 +105,24 @@ CONFIG_ARMV7M_TOOLCHAIN_CODESOURCERYW=y
 #
 # STM32 Configuration Options
 #
+# CONFIG_ARCH_CHIP_STM32L151C6 is not set
+# CONFIG_ARCH_CHIP_STM32L151C8 is not set
+# CONFIG_ARCH_CHIP_STM32L151CB is not set
+# CONFIG_ARCH_CHIP_STM32L151R6 is not set
+# CONFIG_ARCH_CHIP_STM32L151R8 is not set
+# CONFIG_ARCH_CHIP_STM32L151RB is not set
+# CONFIG_ARCH_CHIP_STM32L151V6 is not set
+# CONFIG_ARCH_CHIP_STM32L151V8 is not set
+# CONFIG_ARCH_CHIP_STM32L151VB is not set
+# CONFIG_ARCH_CHIP_STM32L152C6 is not set
+# CONFIG_ARCH_CHIP_STM32L152C8 is not set
+# CONFIG_ARCH_CHIP_STM32L152CB is not set
+# CONFIG_ARCH_CHIP_STM32L152R6 is not set
+# CONFIG_ARCH_CHIP_STM32L152R8 is not set
+# CONFIG_ARCH_CHIP_STM32L152RB is not set
+# CONFIG_ARCH_CHIP_STM32L152V6 is not set
+# CONFIG_ARCH_CHIP_STM32L152V8 is not set
+# CONFIG_ARCH_CHIP_STM32L152VB is not set
 # CONFIG_ARCH_CHIP_STM32F100C8 is not set
 # CONFIG_ARCH_CHIP_STM32F100CB is not set
 # CONFIG_ARCH_CHIP_STM32F100R8 is not set
@@ -117,6 +135,8 @@ CONFIG_ARMV7M_TOOLCHAIN_CODESOURCERYW=y
 # CONFIG_ARCH_CHIP_STM32F100VC is not set
 # CONFIG_ARCH_CHIP_STM32F100VD is not set
 # CONFIG_ARCH_CHIP_STM32F100VE is not set
+# CONFIG_ARCH_CHIP_STM32F103C4 is not set
+# CONFIG_ARCH_CHIP_STM32F103C8 is not set
 # CONFIG_ARCH_CHIP_STM32F103RET6 is not set
 # CONFIG_ARCH_CHIP_STM32F103VCT6 is not set
 # CONFIG_ARCH_CHIP_STM32F103VET6 is not set
@@ -145,7 +165,21 @@ CONFIG_ARCH_CHIP_STM32F303VC=y
 # CONFIG_ARCH_CHIP_STM32F407ZG is not set
 # CONFIG_ARCH_CHIP_STM32F407IE is not set
 # CONFIG_ARCH_CHIP_STM32F407IG is not set
+# CONFIG_ARCH_CHIP_STM32F427V is not set
+# CONFIG_ARCH_CHIP_STM32F427Z is not set
+# CONFIG_ARCH_CHIP_STM32F427I is not set
+# CONFIG_STM32_STM32L15XX is not set
+# CONFIG_STM32_ENERGYLITE is not set
+# CONFIG_STM32_STM32F10XX is not set
+# CONFIG_STM32_VALUELINE is not set
+# CONFIG_STM32_CONNECTIVITYLINE is not set
+# CONFIG_STM32_PERFORMANCELINE is not set
+# CONFIG_STM32_HIGHDENSITY is not set
+# CONFIG_STM32_MEDIUMDENSITY is not set
+# CONFIG_STM32_LOWDENSITY is not set
+# CONFIG_STM32_STM32F20XX is not set
 CONFIG_STM32_STM32F30XX=y
+# CONFIG_STM32_STM32F40XX is not set
 # CONFIG_STM32_DFU is not set
 
 #
@@ -163,11 +197,9 @@ CONFIG_STM32_STM32F30XX=y
 # CONFIG_STM32_DAC2 is not set
 # CONFIG_STM32_I2C1 is not set
 # CONFIG_STM32_I2C2 is not set
-# CONFIG_STM32_IWDG is not set
 CONFIG_STM32_PWR=y
 # CONFIG_STM32_SDIO is not set
 CONFIG_STM32_SPI1=y
-# CONFIG_STM32_SPI2 is not set
 CONFIG_STM32_SYSCFG=y
 # CONFIG_STM32_TIM1 is not set
 # CONFIG_STM32_TIM2 is not set
@@ -183,6 +215,7 @@ CONFIG_STM32_SYSCFG=y
 # CONFIG_STM32_USART1 is not set
 CONFIG_STM32_USART2=y
 CONFIG_STM32_USB=y
+# CONFIG_STM32_IWDG is not set
 # CONFIG_STM32_WWDG is not set
 CONFIG_STM32_SPI=y
 
@@ -193,6 +226,7 @@ CONFIG_STM32_SPI=y
 # CONFIG_STM32_JTAG_FULL_ENABLE is not set
 # CONFIG_STM32_JTAG_NOJNTRST_ENABLE is not set
 CONFIG_STM32_JTAG_SW_ENABLE=y
+# CONFIG_STM32_DISABLE_IDLE_SLEEP_DURING_DEBUG is not set
 # CONFIG_STM32_FORCEPOWER is not set
 # CONFIG_ARCH_BOARD_STM32_CUSTOM_CLOCKCONFIG is not set
 CONFIG_STM32_USART=y
@@ -235,10 +269,14 @@ CONFIG_ARCH_HAVE_VFORK=y
 CONFIG_ARCH_STACKDUMP=y
 # CONFIG_ENDIAN_BIG is not set
 # CONFIG_ARCH_HAVE_RAMFUNCS is not set
+CONFIG_ARCH_HAVE_RAMVECTORS=y
+# CONFIG_ARCH_RAMVECTORS is not set
 
 #
 # Board Settings
 #
+CONFIG_BOARD_LOOPSPERMSEC=6522
+# CONFIG_ARCH_CALIBRATION is not set
 CONFIG_DRAM_START=0x20000000
 CONFIG_DRAM_SIZE=40960
 CONFIG_ARCH_HAVE_INTERRUPTSTACK=y
@@ -278,6 +316,7 @@ CONFIG_NSH_MMCSDMINOR=0
 #
 # RTOS Features
 #
+# CONFIG_BOARD_INITIALIZE is not set
 CONFIG_MSEC_PER_TICK=10
 CONFIG_RR_INTERVAL=200
 # CONFIG_SCHED_INSTRUMENTATION is not set
@@ -293,7 +332,6 @@ CONFIG_START_DAY=27
 # CONFIG_FDCLONE_DISABLE is not set
 # CONFIG_FDCLONE_STDIO is not set
 CONFIG_SDCLONE_DISABLE=y
-# CONFIG_SCHED_WORKQUEUE is not set
 CONFIG_SCHED_WAITPID=y
 # CONFIG_SCHED_STARTHOOK is not set
 # CONFIG_SCHED_ATEXIT is not set
@@ -357,6 +395,7 @@ CONFIG_SPI_EXCHANGE=y
 # CONFIG_RTC is not set
 # CONFIG_WATCHDOG is not set
 # CONFIG_ANALOG is not set
+# CONFIG_AUDIO_DEVICES is not set
 # CONFIG_BCH is not set
 # CONFIG_INPUT is not set
 # CONFIG_LCD is not set
@@ -366,7 +405,6 @@ CONFIG_SPI_EXCHANGE=y
 # CONFIG_PM is not set
 # CONFIG_POWER is not set
 # CONFIG_SENSORS is not set
-# CONFIG_SERCOMM_CONSOLE is not set
 CONFIG_SERIAL=y
 # CONFIG_DEV_LOWCONSOLE is not set
 CONFIG_SERIAL_REMOVABLE=y
@@ -389,14 +427,19 @@ CONFIG_USART2_2STOP=0
 CONFIG_USBDEV=y
 
 #
-# Device Controller Driver Options
+# USB Device Controller Driver Options
 #
 # CONFIG_USBDEV_ISOCHRONOUS is not set
 # CONFIG_USBDEV_DUALSPEED is not set
 CONFIG_USBDEV_SELFPOWERED=y
 # CONFIG_USBDEV_BUSPOWERED is not set
+CONFIG_USBDEV_MAXPOWER=100
 # CONFIG_USBDEV_DMA is not set
 # CONFIG_USBDEV_TRACE is not set
+
+#
+# USB Device Class Driver Options
+#
 # CONFIG_USBDEV_COMPOSITE is not set
 # CONFIG_PL2303 is not set
 CONFIG_CDCACM=y
@@ -449,6 +492,7 @@ CONFIG_CDCACM_PRODUCTSTR="CDC/ACM Serial"
 # CONFIG_FS_FAT is not set
 # CONFIG_FS_NXFFS is not set
 # CONFIG_FS_ROMFS is not set
+# CONFIG_FS_SMARTFS is not set
 # CONFIG_FS_BINFS is not set
 
 #
@@ -467,11 +511,17 @@ CONFIG_SYSLOG_DEVPATH="/dev/ttyS0"
 #
 # Memory Management
 #
+# CONFIG_MM_MULTIHEAP is not set
 # CONFIG_MM_SMALL is not set
 CONFIG_MM_REGIONS=2
 # CONFIG_GRAN is not set
 
 #
+# Audio Support
+#
+# CONFIG_AUDIO is not set
+
+#
 # Binary Formats
 #
 # CONFIG_BINFMT_DISABLE is not set
@@ -496,6 +546,7 @@ CONFIG_LIB_HOMEDIR="/"
 # CONFIG_LIBM is not set
 # CONFIG_NOPRINTF_FIELDWIDTH is not set
 # CONFIG_LIBC_FLOATINGPOINT is not set
+CONFIG_LIB_RAND_ORDER=1
 # CONFIG_EOL_IS_CR is not set
 # CONFIG_EOL_IS_LF is not set
 # CONFIG_EOL_IS_BOTH_CRLF is not set
@@ -511,9 +562,11 @@ CONFIG_LIB_SENDFILE_BUFSIZE=512
 # CONFIG_ARCH_OPTIMIZED_FUNCTIONS is not set
 
 #
-# Non-standard Helper Functions
+# Non-standard Library Support
 #
+# CONFIG_SCHED_WORKQUEUE is not set
 # CONFIG_LIB_KBDCODEC is not set
+# CONFIG_LIB_SLCDCODEC is not set
 
 #
 # Basic CXX Support
@@ -557,8 +610,8 @@ CONFIG_BUILTIN_PROXY_STACKSIZE=1024
 # CONFIG_EXAMPLES_IGMP is not set
 # CONFIG_EXAMPLES_LCDRW is not set
 # CONFIG_EXAMPLES_MM is not set
-# CONFIG_EXAMPLES_MOUNT is not set
 # CONFIG_EXAMPLES_MODBUS is not set
+# CONFIG_EXAMPLES_MOUNT is not set
 CONFIG_EXAMPLES_NSH=y
 # CONFIG_EXAMPLES_NULL is not set
 # CONFIG_EXAMPLES_NX is not set
@@ -578,6 +631,10 @@ CONFIG_EXAMPLES_NSH=y
 # CONFIG_EXAMPLES_ROMFS is not set
 # CONFIG_EXAMPLES_SENDMAIL is not set
 # CONFIG_EXAMPLES_SERLOOP is not set
+# CONFIG_EXAMPLES_SLCD is not set
+# CONFIG_EXAMPLES_SMART_TEST is not set
+# CONFIG_EXAMPLES_SMART is not set
+# CONFIG_EXAMPLES_TCPECHO is not set
 # CONFIG_EXAMPLES_TELNETD is not set
 # CONFIG_EXAMPLES_THTTPD is not set
 # CONFIG_EXAMPLES_TIFF is not set
@@ -590,8 +647,9 @@ CONFIG_EXAMPLES_NSH=y
 # CONFIG_EXAMPLES_WATCHDOG is not set
 
 #
-# Interpreters
+# Graphics Support
 #
+# CONFIG_TIFF is not set
 
 #
 # Interpreters
@@ -621,11 +679,7 @@ CONFIG_EXAMPLES_NSH=y
 # CONFIG_NETUTILS_WEBCLIENT is not set
 
 #
-# ModBus
-#
-
-#
-# FreeModbus
+# FreeModBus
 #
 # CONFIG_MODBUS is not set
 
@@ -677,6 +731,11 @@ CONFIG_NSH_BUILTIN_APPS=y
 # CONFIG_NSH_DISABLE_USLEEP is not set
 # CONFIG_NSH_DISABLE_WGET is not set
 # CONFIG_NSH_DISABLE_XD is not set
+
+#
+# Configure Command Options
+#
+# CONFIG_NSH_CMDOPT_DF_H is not set
 CONFIG_NSH_CODECS_BUFSIZE=128
 CONFIG_NSH_FILEIOSIZE=512
 CONFIG_NSH_LINELEN=64
@@ -715,6 +774,10 @@ CONFIG_NSH_ARCHINIT=y
 # CONFIG_SYSTEM_INSTALL is not set
 
 #
+# FLASH Erase-all Command
+#
+
+#
 # readline()
 #
 CONFIG_SYSTEM_READLINE=y
diff --git a/nuttx/configs/stm32f4discovery/README.txt b/nuttx/configs/stm32f4discovery/README.txt
index 684c916f5..e94bd466b 100644
--- a/nuttx/configs/stm32f4discovery/README.txt
+++ b/nuttx/configs/stm32f4discovery/README.txt
@@ -1641,6 +1641,12 @@ Where <subdir> is one of the following:
        configuration so nothing should appear on UART2 unless you enable
        some debug output or enable the USB monitor.
 
+       NOTE:  Using the SYSLOG to get debug output has limitations.  Among
+       those are that you cannot get debug output from interrupt handlers.
+       So, in particularly, debug output is not a useful way to debug the
+       USB device controller driver.  Instead, use the USB monitor with
+       USB debug off and USB trance on (see below).
+
     4. Enabling USB monitor SYSLOG output.  If tracing is enabled, the USB
        device will save encoded trace output in in-memory buffer; if the
        USB monitor is enabled, that trace buffer will be periodically
diff --git a/nuttx/configs/sure-pic32mx/README.txt b/nuttx/configs/sure-pic32mx/README.txt
index 7592538ff..48877a498 100644
--- a/nuttx/configs/sure-pic32mx/README.txt
+++ b/nuttx/configs/sure-pic32mx/README.txt
@@ -853,10 +853,11 @@ Where <subdir> is one of the following:
       You could also use the non-standard PL2303 serial device instead of
       the standard CDC/ACM serial device by changing:
 
-        CONFIG_CDCACM=n             : Disable the CDC/ACM serial device class
-        CONFIG_CDCACM_CONSOLE=n     : The CDC/ACM serial device is NOT the console
-        CONFIG_PL2303=y             : The Prolifics PL2303 emulation is enabled
-        CONFIG_PL2303_CONSOLE=y     : The PL2303 serial device is the console
+        Drivers->USB Device Driver Support
+          CONFIG_CDCACM=n             : Disable the CDC/ACM serial device class
+          CONFIG_CDCACM_CONSOLE=n     : The CDC/ACM serial device is NOT the console
+          CONFIG_PL2303=y             : The Prolifics PL2303 emulation is enabled
+          CONFIG_PL2303_CONSOLE=y     : The PL2303 serial device is the console
 
       Why would you want to use a non-standard USB serial driver?  You might
       to use the PL2303 driver with a Windows host because it should
@@ -864,9 +865,9 @@ Where <subdir> is one of the following:
       some effort to get Windows to recognize the CDC/ACM device).
 
     4. Since this configuration is current set for the "DB_DP11215 PIC32
-       Storage Demo Board," USART2 is available and is configured to used as
+       Storage Demo Board," UART2 is available and is configured to used as
        the SYSLOG device.  That means that all debug output will be directed
-       out USART2.  Debug output is not enabled by default, however, so these
+       out UART2.  Debug output is not enabled by default, however, so these
        settings do nothing until you enable debug ouput.
 
         Device Drivers -> System Logging Device Options:
@@ -916,7 +917,9 @@ Where <subdir> is one of the following:
           CONFIG_SYSTEM_USBMONITOR_TRACECONTROLLER=y
           CONFIG_SYSTEM_USBMONITOR_TRACEINTERRUPTS=y
 
-       NOTE: USB debug output should not be enabled in this case.
+       NOTE: USB debug output also be enabled in this case.  Both will appear
+       on the serial SYSLOG output.  However, the debug output will be
+       asynchronous with the trace output and, hence, difficult to interpret.
 
     6. If you want to try this configuration on the DB-DP11212 PIC32 General
        Purpose Demo Board", here are the changes that you should make: