dfu: Introduction of the "dfu_checksum_method" env variable for checksum method setting

Up till now the CRC32 of received data was calculated unconditionally.
The standard crc32 implementation causes long delays when large images
were uploaded.

The "dfu_checksum_method" environment variable gives the opportunity to
enable on demand (when e.g. debugging) the crc32 calculation.
It can be done without need to recompile the u-boot binary.

By default the crc32 is not calculated.

Tests results:
400 MiB ums.img file
With 		crc32 calculation: 65 sec [avg 6.29 MB/s]
Without 		crc32 calculation: 25 sec [avg 16.17 MB/s]

Signed-off-by: Lukasz Majewski <l.majewski@samsung.com>

diff --git a/drivers/dfu/dfu.c b/drivers/dfu/dfu.c
index c8c2137..a133f38 100644 (file)
--- a/drivers/dfu/dfu.c
+++ b/drivers/dfu/dfu.c
@@ -20,6 +20,7 @@ static bool dfu_reset_request;
 static LIST_HEAD(dfu_list);
 static int dfu_alt_num;
 static int alt_num_count;
+static int dfu_checksum_method;
 
 bool dfu_reset(void)
 {
@@ -99,6 +100,23 @@ unsigned char *dfu_get_buf(void)
        return dfu_buf;
 }
 
+static int dfu_get_checksum_method(void)
+{
+       char *s;
+
+       s = getenv("dfu_checksum_method");
+       if (!s)
+               return DFU_NO_CHECKSUM;
+
+       if (!strcmp(s, "crc32")) {
+               debug("%s: DFU checksum method: %s\n", __func__, s);
+               return DFU_CRC32;
+       } else {
+               error("DFU checksum method: %s not supported!\n", s);
+               return -EINVAL;
+       }
+}
+
 static int dfu_write_buffer_drain(struct dfu_entity *dfu)
 {
        long w_size;
@@ -109,8 +127,8 @@ static int dfu_write_buffer_drain(struct dfu_entity *dfu)
        if (w_size == 0)
                return 0;
 
-       /* update CRC32 */
-       dfu->crc = crc32(dfu->crc, dfu->i_buf_start, w_size);
+       if (dfu_checksum_method == DFU_CRC32)
+               dfu->crc = crc32(dfu->crc, dfu->i_buf_start, w_size);
 
        ret = dfu->write_medium(dfu, dfu->offset, dfu->i_buf_start, &w_size);
        if (ret)
@@ -202,8 +220,9 @@ int dfu_write(struct dfu_entity *dfu, void *buf, int size, int blk_seq_num)
                /* Now try and flush to the medium if needed. */
                if (dfu->flush_medium)
                        ret = dfu->flush_medium(dfu);
-               printf("\nDFU complete CRC32: 0x%08x\n", dfu->crc);
 
+               if (dfu_checksum_method == DFU_CRC32)
+                       printf("\nDFU complete CRC32: 0x%08x\n", dfu->crc);
                /* clear everything */
                dfu_free_buf();
                dfu->crc = 0;
@@ -232,7 +251,8 @@ static int dfu_read_buffer_fill(struct dfu_entity *dfu, void *buf, int size)
                /* consume */
                if (chunk > 0) {
                        memcpy(buf, dfu->i_buf, chunk);
-                       dfu->crc = crc32(dfu->crc, buf, chunk);
+                       if (dfu_checksum_method == DFU_CRC32)
+                               dfu->crc = crc32(dfu->crc, buf, chunk);
                        dfu->i_buf += chunk;
                        dfu->b_left -= chunk;
                        dfu->r_left -= chunk;
@@ -316,7 +336,9 @@ int dfu_read(struct dfu_entity *dfu, void *buf, int size, int blk_seq_num)
        }
 
        if (ret < size) {
-               debug("%s: %s CRC32: 0x%x\n", __func__, dfu->name, dfu->crc);
+               if (dfu_checksum_method == DFU_CRC32)
+                       debug("%s: %s CRC32: 0x%x\n", __func__, dfu->name,
+                             dfu->crc);
                puts("\nUPLOAD ... done\nCtrl+C to exit ...\n");
 
                dfu_free_buf();
@@ -391,6 +413,11 @@ int dfu_config_entities(char *env, char *interface, int num)
        dfu_alt_num = dfu_find_alt_num(env);
        debug("%s: dfu_alt_num=%d\n", __func__, dfu_alt_num);
 
+       ret = dfu_get_checksum_method();
+       if (ret < 0)
+               return ret;
+       dfu_checksum_method = ret;
+
        dfu = calloc(sizeof(*dfu), dfu_alt_num);
        if (!dfu)
                return -1;

diff --git a/include/dfu.h b/include/dfu.h
index d014107..e7a9d4c 100644 (file)
--- a/include/dfu.h
+++ b/include/dfu.h
@@ -37,6 +37,11 @@ enum dfu_op {
        DFU_OP_WRITE,
 };
 
+enum dfu_checksum {
+       DFU_NO_CHECKSUM = 0,
+       DFU_CRC32,
+};
+
 #define DFU_NOT_SUPPORTED -1
 
 struct mmc_internal_data {