[U-Boot] [PATCH] dfu: fix some issues with reads/uploads

[Stephen Warren]

From: Stephen Warren <swarren at nvidia.com>

DFU read support appears to rely upon dfu->read_medium() updating the
passed-by-reference len parameter to indicate the remaining size
available for reading.

dfu_read_medium_mmc() never does this, and the implementation of
dfu_read_medium_nand() will only work if called just once; it hard-codes
the value to the total size of the NAND device irrespective of read
offset.

I believe that overloading dfu->read_medium() is confusing. As such,
this patch introduces a new function dfu->get_medium_size() which can
be used to explicitly find out the medium size, and nothing else.
dfu_read() is modified to use this function to set the initial value for
dfu->r_left, rather than attempting to use the side-effects of
dfu->read_medium() for this purpose.

Due to this change, dfu_read() must initially set dfu->b_left to 0, since
no data has been read.

dfu_read_buffer_fill() must also be modified not to adjust dfu->r_left
when simply copying data from dfu->i_buf_start to the upload request
buffer. r_left represents the amount of data left to be read from HW.
That value is not affected by the memcpy(), but only by calls to
dfu->read_medium().

After this change, I can read from either a 4MB or 1.5MB chunk of a 4MB
eMMC boot partion with CONFIG_SYS_DFU_DATA_BUF_SIZE==1MB. Without this
change, attempting to do that would result in DFU read returning no data
at all due to r_left never being set.

Signed-off-by: Stephen Warren <swarren at nvidia.com>
---
 drivers/dfu/dfu.c      |  9 ++-------
 drivers/dfu/dfu_mmc.c  |  6 ++++++
 drivers/dfu/dfu_nand.c |  7 ++++++-
 drivers/dfu/dfu_ram.c  | 11 ++++++-----
 include/dfu.h          |  2 ++
 5 files changed, 22 insertions(+), 13 deletions(-)

diff --git a/drivers/dfu/dfu.c b/drivers/dfu/dfu.c
index a93810934ac9..af97234390c7 100644
--- a/drivers/dfu/dfu.c
+++ b/drivers/dfu/dfu.c
@@ -241,7 +241,6 @@ static int dfu_read_buffer_fill(struct dfu_entity *dfu, void *buf, int size)
 			dfu->crc = crc32(dfu->crc, buf, chunk);
 			dfu->i_buf += chunk;
 			dfu->b_left -= chunk;
-			dfu->r_left -= chunk;
 			size -= chunk;
 			buf += chunk;
 			readn += chunk;
@@ -287,11 +286,7 @@ int dfu_read(struct dfu_entity *dfu, void *buf, int size, int blk_seq_num)
 		if (dfu->i_buf_start == NULL)
 			return -ENOMEM;
 
-		ret = dfu->read_medium(dfu, 0, dfu->i_buf_start, &dfu->r_left);
-		if (ret != 0) {
-			debug("%s: failed to get r_left\n", __func__);
-			return ret;
-		}
+		dfu->r_left = dfu->get_medium_size(dfu);
 
 		debug("%s: %s %ld [B]\n", __func__, dfu->name, dfu->r_left);
 
@@ -300,7 +295,7 @@ int dfu_read(struct dfu_entity *dfu, void *buf, int size, int blk_seq_num)
 		dfu->offset = 0;
 		dfu->i_buf_end = dfu_get_buf() + dfu_buf_size;
 		dfu->i_buf = dfu->i_buf_start;
-		dfu->b_left = min(dfu_buf_size, dfu->r_left);
+		dfu->b_left = 0;
 
 		dfu->bad_skip = 0;
 
diff --git a/drivers/dfu/dfu_mmc.c b/drivers/dfu/dfu_mmc.c
index 63cc876612c9..aa077c052f39 100644
--- a/drivers/dfu/dfu_mmc.c
+++ b/drivers/dfu/dfu_mmc.c
@@ -196,6 +196,11 @@ int dfu_flush_medium_mmc(struct dfu_entity *dfu)
 	return ret;
 }
 
+long dfu_get_medium_size_mmc(struct dfu_entity *dfu)
+{
+	return dfu->data.mmc.lba_size * dfu->data.mmc.lba_blk_size;
+}
+
 int dfu_read_medium_mmc(struct dfu_entity *dfu, u64 offset, void *buf,
 		long *len)
 {
@@ -316,6 +321,7 @@ int dfu_fill_entity_mmc(struct dfu_entity *dfu, char *s)
 	}
 
 	dfu->dev_type = DFU_DEV_MMC;
+	dfu->get_medium_size = dfu_get_medium_size_mmc;
 	dfu->read_medium = dfu_read_medium_mmc;
 	dfu->write_medium = dfu_write_medium_mmc;
 	dfu->flush_medium = dfu_flush_medium_mmc;
diff --git a/drivers/dfu/dfu_nand.c b/drivers/dfu/dfu_nand.c
index ccdbef6b75f2..e1c9a8849246 100644
--- a/drivers/dfu/dfu_nand.c
+++ b/drivers/dfu/dfu_nand.c
@@ -114,6 +114,11 @@ static int dfu_write_medium_nand(struct dfu_entity *dfu,
 	return ret;
 }
 
+long dfu_get_medium_size_nand(struct dfu_entity *dfu)
+{
+	return dfu->data.nand.size;
+}
+
 static int dfu_read_medium_nand(struct dfu_entity *dfu, u64 offset, void *buf,
 		long *len)
 {
@@ -121,7 +126,6 @@ static int dfu_read_medium_nand(struct dfu_entity *dfu, u64 offset, void *buf,
 
 	switch (dfu->layout) {
 	case DFU_RAW_ADDR:
-		*len = dfu->data.nand.size;
 		ret = nand_block_read(dfu, offset, buf, len);
 		break;
 	default:
@@ -220,6 +224,7 @@ int dfu_fill_entity_nand(struct dfu_entity *dfu, char *s)
 		return -1;
 	}
 
+	dfu->get_medium_size = dfu_get_medium_size_nand;
 	dfu->read_medium = dfu_read_medium_nand;
 	dfu->write_medium = dfu_write_medium_nand;
 	dfu->flush_medium = dfu_flush_medium_nand;
diff --git a/drivers/dfu/dfu_ram.c b/drivers/dfu/dfu_ram.c
index 335a8e1f2491..b6c6e60c443c 100644
--- a/drivers/dfu/dfu_ram.c
+++ b/drivers/dfu/dfu_ram.c
@@ -41,14 +41,14 @@ static int dfu_write_medium_ram(struct dfu_entity *dfu, u64 offset,
 	return dfu_transfer_medium_ram(DFU_OP_WRITE, dfu, offset, buf, len);
 }
 
+long dfu_get_medium_size_ram(struct dfu_entity *dfu)
+{
+	return dfu->data.ram.size;
+}
+
 static int dfu_read_medium_ram(struct dfu_entity *dfu, u64 offset,
 			       void *buf, long *len)
 {
-	if (!*len) {
-		*len = dfu->data.ram.size;
-		return 0;
-	}
-
 	return dfu_transfer_medium_ram(DFU_OP_READ, dfu, offset, buf, len);
 }
 
@@ -69,6 +69,7 @@ int dfu_fill_entity_ram(struct dfu_entity *dfu, char *s)
 	dfu->data.ram.size = simple_strtoul(s, &s, 16);
 
 	dfu->write_medium = dfu_write_medium_ram;
+	dfu->get_medium_size = dfu_get_medium_size_ram;
 	dfu->read_medium = dfu_read_medium_ram;
 
 	dfu->inited = 0;
diff --git a/include/dfu.h b/include/dfu.h
index 26ffbc8e81d2..0cca601d47af 100644
--- a/include/dfu.h
+++ b/include/dfu.h
@@ -96,6 +96,8 @@ struct dfu_entity {
 		struct ram_internal_data ram;
 	} data;
 
+	long (*get_medium_size)(struct dfu_entity *dfu);
+
 	int (*read_medium)(struct dfu_entity *dfu,
 			u64 offset, void *buf, long *len);
 
-- 
1.8.1.5