Addition rwbuffer interfaces should not be enabled unless they are needed; if rwbuffer support is enabled, it should not be unconditionally enabled in SMART and FTL

drivers/Kconfig

@@ -62,6 +62,23 @@ config DRVR_READAHEAD
 		Enable generic read-ahead buffering support that can be used by a
 		variety of drivers.
 
+if DRVR_WRITEBUFFER || DRVR_READAHEAD
+
+config DRVR_READBYTES
+	bool "Support byte read method"
+	default y if MTD_BYTE_WRITE
+	default n if !MTD_BYTE_WRITE
+
+config DRVR_REMOVABLE
+	bool "Support removable media"
+	default n
+
+config DRVR_INVALIDATE
+	bool "Support cache invalidation"
+	default n
+
+endif # DRVR_WRITEBUFFER || DRVR_READAHEAD
+
 config RAMDISK
 	bool "RAM Disk Support"
 	default n

drivers/mtd/Kconfig

@@ -26,6 +26,16 @@ config MTD_PARTITION
 		managing the sub-region of flash beginning at 'offset' (in blocks)
 		and of size 'nblocks' on the device specified by 'mtd'.
 
+config FTL_WRITEBUFFER
+	bool "Enable write buffering in the FTL layer"
+	default n
+	depends on DRVR_WRITEBUFFER
+
+config FTL_READAHEAD
+	bool "Enable read-ahead buffering in the FTL layer"
+	default n
+	depends on DRVR_READAHEAD
+
 config MTD_SECT512
 	bool "512B sector conversion"
 	default n
@@ -70,6 +80,8 @@ config MTD_WRBUFFER
 	bool "Enable MTD write buffering
 	default n
 	depends on DRVR_WRITEBUFFER
+	select DRVR_INVALIDATE
+	select DRVR_READBYTES
 	---help---
 		Build the mtd_rwbuffer layer and enable support for write buffering.
 
@@ -87,6 +99,8 @@ config MTD_READAHEAD
 	bool "Enable MTD read-ahead buffering
 	default n
 	depends on DRVR_READAHEAD
+	select DRVR_INVALIDATE
+	select DRVR_READBYTES
 	---help---
 		Build the mtd_rwbuffer layer and enable support for read-ahead buffering.
 
@@ -360,15 +374,28 @@ config MTD_SMART
 		(typically 2K - 4K based on memory size) and relocating sectors as needed when
 		an erase block needs to be erased.
 
+if MTD_SMART
+
 config MTD_SMART_SECTOR_SIZE
 	int "SMART Device sector size"
-    depends on MTD_SMART
 	default 1024
 	---help---
-		Sets the size of a single alloction on the SMART device.  Larger sector sizes
+		Sets the size of a single allocation on the SMART device.  Larger sector sizes
 		reduce overhead per sector, but cause more wasted space with a lot of smaller
 		files.
 
+config MTD_SMART_WRITEBUFFER
+	bool "Enable SMART write bufferingr"
+	default n
+	depends on DRVR_WRITEBUFFER
+
+config MTD_SMART_READAHEAD
+	bool "Enable SMART read-ahead buffering"
+	default n
+	depends on DRVR_READAHEAD
+
+endif # MTD_SMART
+
 config MTD_RAMTRON
 	bool "SPI-based RAMTRON NVRAM Devices FM25V10"
 	default n

drivers/mtd/ftl.c

@@ -59,8 +59,8 @@
  * Pre-processor Definitions
  ****************************************************************************/
 
-#if defined(CONFIG_DRVR_READAHEAD) || defined(CONFIG_DRVR_WRITEBUFFER)
+#if defined(CONFIG_FTL_READAHEAD) || defined(CONFIG_FTL_WRITEBUFFER)
-#  define CONFIG_FTL_RWBUFFER 1
+#  define FTL_HAVE_RWBUFFER 1
 #endif
 
 /****************************************************************************
@@ -71,7 +71,7 @@ struct ftl_struct_s
 {
   FAR struct mtd_dev_s *mtd;     /* Contained MTD interface */
   struct mtd_geometry_s geo;     /* Device geometry */
-#ifdef CONFIG_FTL_RWBUFFER
+#ifdef FTL_HAVE_RWBUFFER
   struct rwbuffer_s     rwb;     /* Read-ahead/write buffer support */
 #endif
   uint16_t              blkper;  /* R/W blocks per erase block */
@@ -188,7 +188,7 @@ static ssize_t ftl_read(FAR struct inode *inode, unsigned char *buffer,
   DEBUGASSERT(inode && inode->i_private);
 
   dev = (FAR struct ftl_struct_s *)inode->i_private;
-#ifdef CONFIG_DRVR_READAHEAD
+#ifdef CONFIG_FTL_READAHEAD
   return rwb_read(&dev->rwb, start_sector, nsectors, buffer);
 #else
   return ftl_reload(dev, buffer, start_sector, nsectors);
@@ -389,7 +389,7 @@ static ssize_t ftl_write(FAR struct inode *inode, const unsigned char *buffer,
 
   DEBUGASSERT(inode && inode->i_private);
   dev = (struct ftl_struct_s *)inode->i_private;
-#ifdef CONFIG_DRVR_WRITEBUFFER
+#ifdef CONFIG_FTL_WRITEBUFFER
   return rwb_write(&dev->rwb, start_sector, nsectors, buffer);
 #else
   return ftl_flush(dev, buffer, start_sector, nsectors);
@@ -562,17 +562,17 @@ int ftl_initialize(int minor, FAR struct mtd_dev_s *mtd)
 
       /* Configure read-ahead/write buffering */
 
-#ifdef CONFIG_FTL_RWBUFFER
+#ifdef FTL_HAVE_RWBUFFER
       dev->rwb.blocksize   = dev->geo.blocksize;
       dev->rwb.nblocks     = dev->geo.neraseblocks * dev->blkper;
       dev->rwb.dev         = (FAR void *)dev;
 
-#if defined(CONFIG_FS_WRITABLE) && defined(CONFIG_DRVR_WRITEBUFFER)
+#if defined(CONFIG_FS_WRITABLE) && defined(CONFIG_FTL_WRITEBUFFER)
       dev->rwb.wrmaxblocks = dev->blkper;
       dev->rwb.wrflush     = ftl_flush;
 #endif
 
-#ifdef CONFIG_DRVR_READAHEAD
+#ifdef CONFIG_FTL_READAHEAD
       dev->rwb.rhmaxblocks = dev->blkper;
       dev->rwb.rhreload    = ftl_reload;
 #endif

drivers/mtd/mtd_rwbuffer.c

@@ -62,6 +62,14 @@
  * Pre-processor Definitions
  ************************************************************************************/
 
+#ifndef CONFIG_DRVR_INVALIDATE
+#  error This driver requires CONFIG_DRVR_INVALIDATE
+#endif
+
+#ifndef CONFIG_DRVR_READBYTES
+#  error This driver requires CONFIG_DRVR_READBYTES
+#endif
+
 #ifndef CONFIG_MTD_NWRBLOCKS
 #  define CONFIG_MTD_NWRBLOCKS 4
 #endif
@@ -233,7 +241,7 @@ static ssize_t mtd_read(FAR struct mtd_dev_s *dev, off_t offset, size_t nbytes,
    * needs to read any data.
    */
 
-  return mtd_readbytes(&priv->rwb, offset, nbytes, buffer);
+  return rwb_readbytes(&priv->rwb, offset, nbytes, buffer);
 }
 
 /************************************************************************************

drivers/mtd/smart.c

@@ -105,9 +105,9 @@
                                              * other for our use, such as format
                                              * sector, etc. */
 
-#if defined(CONFIG_DRVR_READAHEAD) || (defined(CONFIG_DRVR_WRITABLE) && \
+#if defined(CONFIG_MTD_SMART_READAHEAD) || (defined(CONFIG_DRVR_WRITABLE) && \
-    defined(CONFIG_DRVR_WRITEBUFFER))
+    defined(CONFIG_MTD_SMART_WRITEBUFFER))
-#  define CONFIG_SMART_RWBUFFER 1
+#  define SMART_HAVE_RWBUFFER 1
 #endif
 
 #ifndef CONFIG_MTD_SMART_SECTOR_SIZE

drivers/rwbuffer.c

@@ -389,7 +389,7 @@ static int rwb_rhreload(struct rwbuffer_s *rwb, off_t startblock)
  *
  ****************************************************************************/
 
-#ifdef CONFIG_DRVR_WRITEBUFFER
+#if defined(CONFIG_DRVR_WRITEBUFFER) && defined(CONFIG_DRVR_INVALIDATE)
 int rwb_invalidate_writebuffer(FAR struct rwbuffer_s *rwb,
                                off_t startblock, size_t blockcount)
 {
@@ -525,7 +525,7 @@ int rwb_invalidate_writebuffer(FAR struct rwbuffer_s *rwb,
  *
  ****************************************************************************/
 
-#ifdef CONFIG_DRVR_READAHEAD
+#if defined(CONFIG_DRVR_READAHEAD)  && defined(CONFIG_DRVR_INVALIDATE)
 int rwb_invalidate_readahead(FAR struct rwbuffer_s *rwb,
                                off_t startblock, size_t blockcount)
 {
@@ -924,6 +924,7 @@ int rwb_write(FAR struct rwbuffer_s *rwb, off_t startblock,
  *
  ****************************************************************************/
 
+#ifdef CONFIG_DRVR_REMOVABLE
 int rwb_mediaremoved(FAR struct rwbuffer_s *rwb)
 {
 #ifdef CONFIG_DRVR_WRITEBUFFER
@@ -946,6 +947,7 @@ int rwb_mediaremoved(FAR struct rwbuffer_s *rwb)
 
   return OK;
 }
+#endif
 
 /****************************************************************************
  * Name: rwb_invalidate
@@ -955,6 +957,7 @@ int rwb_mediaremoved(FAR struct rwbuffer_s *rwb)
  *
  ****************************************************************************/
 
+#ifdef CONFIG_DRVR_INVALIDATE
 int rwb_invalidate(FAR struct rwbuffer_s *rwb,
                    off_t startblock, size_t blockcount)
 {
@@ -980,6 +983,7 @@ int rwb_invalidate(FAR struct rwbuffer_s *rwb,
 
   return OK;
 }
+#endif
 
 #endif /* CONFIG_DRVR_WRITEBUFFER || CONFIG_DRVR_READAHEAD */
 

include/nuttx/rwbuffer.h

@@ -186,14 +186,21 @@ ssize_t rwb_write(FAR struct rwbuffer_s *rwb,
 
 /* Character oriented transfers */
 
-ssize_t mtd_readbytes(FAR struct rwbuffer_s *dev, off_t offset,
+#ifdef CONFIG_DRVR_READBYTES
+ssize_t rwb_readbytes(FAR struct rwbuffer_s *dev, off_t offset,
                       size_t nbytes, FAR uint8_t *buffer);
+#endif
 
 /* Media events */
 
+#ifdef CONFIG_DRVR_REMOVABLE
 int rwb_mediaremoved(FAR struct rwbuffer_s *rwb);
+#endif
+
+#ifdef CONFIG_DRVR_INVALIDATE
 int rwb_invalidate(FAR struct rwbuffer_s *rwb,
                    off_t startblock, size_t blockcount);
+#endif
 
 #undef EXTERN
 #if defined(__cplusplus)