NAND: Do not write or read a whole block if it is larger than the environment

Environment can be smaller than NAND block size, do not need to read a whole
block and minimum for writing is one page. Also remove an unused variable.

Signed-off-by: Guennadi Liakhovetski <lg@denx.de>
Signed-off-by: Scott Wood <scottwood@freescale.com>

diff --git a/common/env_nand.c b/common/env_nand.c
index 104f0856af2a3af7254d06451c47bee4485e89df..a8f0de7ae24b29a835771e3fb25fb8c7141a2ebc 100644 (file)
--- a/common/env_nand.c
+++ b/common/env_nand.c
@@ -159,22 +159,23 @@ int writeenv(size_t offset, u_char *buf)
 {
        size_t end = offset + CFG_ENV_RANGE;
        size_t amount_saved = 0;
-       size_t blocksize;
+       size_t blocksize, len;
 
        u_char *char_ptr;
 
        blocksize = nand_info[0].erasesize;
+       len = min(blocksize, CFG_ENV_SIZE);
 
        while (amount_saved < CFG_ENV_SIZE && offset < end) {
                if (nand_block_isbad(&nand_info[0], offset)) {
                        offset += blocksize;
                } else {
                        char_ptr = &buf[amount_saved];
-                       if (nand_write(&nand_info[0], offset, &blocksize,
+                       if (nand_write(&nand_info[0], offset, &len,
                                        char_ptr))
                                return 1;
                        offset += blocksize;
-                       amount_saved += blocksize;
+                       amount_saved += len;
                }
        }
        if (amount_saved != CFG_ENV_SIZE)
@@ -261,21 +262,22 @@ int readenv (size_t offset, u_char * buf)
 {
        size_t end = offset + CFG_ENV_RANGE;
        size_t amount_loaded = 0;
-       size_t blocksize;
+       size_t blocksize, len;
 
        u_char *char_ptr;
 
        blocksize = nand_info[0].erasesize;
+       len = min(blocksize, CFG_ENV_SIZE);
 
        while (amount_loaded < CFG_ENV_SIZE && offset < end) {
                if (nand_block_isbad(&nand_info[0], offset)) {
                        offset += blocksize;
                } else {
                        char_ptr = &buf[amount_loaded];
-                       if (nand_read(&nand_info[0], offset, &blocksize, char_ptr))
+                       if (nand_read(&nand_info[0], offset, &len, char_ptr))
                                return 1;
                        offset += blocksize;
-                       amount_loaded += blocksize;
+                       amount_loaded += len;
                }
        }
        if (amount_loaded != CFG_ENV_SIZE)
@@ -345,12 +347,10 @@ void env_relocate_spec (void)
 void env_relocate_spec (void)
 {
 #if !defined(ENV_IS_EMBEDDED)
-       size_t total;
        int ret;
 
-       total = CFG_ENV_SIZE;
        ret = readenv(CFG_ENV_OFFSET, (u_char *) env_ptr);
-       if (ret || total != CFG_ENV_SIZE)
+       if (ret)
                return use_default();
 
        if (crc32(0, env_ptr->data, ENV_SIZE) != env_ptr->crc)