[U-Boot] [PATCH v2] fat: Define MAX_CLUSTSIZE only if not defined in config

[Siva Durga Prasad Paladugu]

Define the MAX_CLUSTSIZE to default of 65536 only if
CONFIG_FS_FAT_MAX_CLUSTSIZE is not defined in board
specific config file.
Also please define your own MAX_CLUSTSIZE value if
CONFIG_FS_FAT_MAX_CLUSTSIZE is defined.
This option has been provided to save memory in some
memory constrained cases.

Signed-off-by: Siva Durga Prasad Paladugu <sivadur at xilinx.com>
---

Changes in v2:
-Defined CONFIG_FS_FAT_MAX_CLUSTSIZE and documented as
per review comment.

 README        |    7 +++++++
 include/fat.h |    2 ++
 2 files changed, 9 insertions(+), 0 deletions(-)

diff --git a/README b/README
index 5f89552..0d947cb 100644
--- a/README
+++ b/README
@@ -1613,6 +1613,13 @@ CBFS (Coreboot Filesystem) support
 		filesystem. Available commands are cbfsinit, cbfsinfo, cbfsls
 		and cbfsload.
 
+- FAT(File Allocation Table) filesystem write/read buffer size:
+		CONFIG_FS_FAT_MAX_CLUSTSIZE
+
+		If this macro is not defined then the default MAX_CLUSTSIZE
+		is defined with 65536 else specify your own MAX_CLUSTSSIZE
+		value.
+
 - Keyboard Support:
 		CONFIG_ISA_KEYBOARD
 
diff --git a/include/fat.h b/include/fat.h
index 81d9790..8b67851 100644
--- a/include/fat.h
+++ b/include/fat.h
@@ -18,7 +18,9 @@
 #define VFAT_MAXSEQ		9   /* Up to 9 of 13 2-byte UTF-16 entries */
 #define PREFETCH_BLOCKS		2
 
+#ifndef CONFIG_FS_FAT_MAX_CLUSTSIZE
 #define MAX_CLUSTSIZE	65536
+#endif
 #define DIRENTSPERBLOCK	(mydata->sect_size / sizeof(dir_entry))
 #define DIRENTSPERCLUST	((mydata->clust_size * mydata->sect_size) / \
 			 sizeof(dir_entry))
-- 
1.7.4