File content as of revision 4:291477e8690d:

diff --git a/features/filesystem/fat/ChaN/ff.cpp b/features/filesystem/fat/ChaN/ff.cpp
index 7e4561d809..3bda25e4a9 100644
--- a/features/filesystem/fat/ChaN/ff.cpp
+++ b/features/filesystem/fat/ChaN/ff.cpp
@@ -3800,7 +3800,9 @@ FRESULT f_read (
 					cc = fs->csize - csect;
 				}
 				if (disk_read(fs->pdrv, rbuff, sect, cc) != RES_OK) ABORT(fs, FR_DISK_ERR);
-#if !FF_FS_READONLY && FF_FS_MINIMIZE <= 2		/* Replace one of the read sectors with cached data if it contains a dirty sector */
+
+/*
+#if !FF_FS_READONLY && FF_FS_MINIMIZE <= 2
 #if FF_FS_TINY
 				if (fs->wflag && fs->winsect - sect < cc) {
 					mem_cpy(rbuff + ((fs->winsect - sect) * SS(fs)), fs->win, SS(fs));
@@ -3811,6 +3813,8 @@ FRESULT f_read (
 				}
 #endif
 #endif
+*/
+
 				rcnt = SS(fs) * cc;				/* Number of bytes transferred */
 				continue;
 			}
@@ -3921,19 +3925,20 @@ FRESULT f_write (
 					cc = fs->csize - csect;
 				}
 				if (disk_write(fs->pdrv, wbuff, sect, cc) != RES_OK) ABORT(fs, FR_DISK_ERR);
+/*
 #if FF_FS_MINIMIZE <= 2
 #if FF_FS_TINY
-				if (fs->winsect - sect < cc) {	/* Refill sector cache if it gets invalidated by the direct write */
+				if (fs->winsect - sect < cc) {
 					mem_cpy(fs->win, wbuff + ((fs->winsect - sect) * SS(fs)), SS(fs));
 					fs->wflag = 0;
 				}
 #else
-				if (fp->sect - sect < cc) { /* Refill sector cache if it gets invalidated by the direct write */
+				if (fp->sect - sect < cc) {
 					mem_cpy(fp->buf, wbuff + ((fp->sect - sect) * SS(fs)), SS(fs));
 					fp->flag &= (BYTE)~FA_DIRTY;
 				}
 #endif
-#endif
+#endif*/
 				wcnt = SS(fs) * cc;		/* Number of bytes transferred */
 #if FLUSH_ON_NEW_SECTOR
                 need_sync = true;
diff --git a/features/filesystem/fat/ChaN/ffconf.h b/features/filesystem/fat/ChaN/ffconf.h
index 22e1294277..f446778695 100644
--- a/features/filesystem/fat/ChaN/ffconf.h
+++ b/features/filesystem/fat/ChaN/ffconf.h
@@ -151,7 +151,7 @@
 */
 
 
-#define FF_FS_RPATH		1
+#define FF_FS_RPATH		0
 /* This option configures support for relative path.
 /
 /   0: Disable relative path and remove related functions.
@@ -164,7 +164,7 @@
 / Drive/Volume Configurations
 /---------------------------------------------------------------------------*/
 
-#define FF_VOLUMES		4
+#define FF_VOLUMES		1
 /* Number of volumes (logical drives) to be used. (1-10) */
 
 
@@ -219,7 +219,7 @@
 / System Configurations
 /---------------------------------------------------------------------------*/
 
-#define FF_FS_TINY		1
+#define FF_FS_TINY		0
 /* This option switches tiny buffer configuration. (0:Normal or 1:Tiny)
 /  At the tiny configuration, size of file object (FIL) is shrinked FF_MAX_SS bytes.
 /  Instead of private sector buffer eliminated from the file object, common sector
@@ -289,7 +289,7 @@
 /* #include <windows.h>	// O/S definitions  */
 
 #define FLUSH_ON_NEW_CLUSTER    0   /* Sync the file on every new cluster */
-#define FLUSH_ON_NEW_SECTOR     1   /* Sync the file on every new sector */
+#define FLUSH_ON_NEW_SECTOR     0   /* Sync the file on every new sector */
 /* Only one of these two defines needs to be set to 1. If both are set to 0
    the file is only sync when closed.
    Clusters are group of sectors (eg: 8 sectors). Flushing on new cluster means