[U-Boot] [PATCH 06/10] dfu: mmc: buffer file reads too

[Lukasz Majewski <l.majewski@samsung.com>]

Hi Stephen,

> From: Stephen Warren <swarren@nvidia.com>
> 
> When writing to files in a filesystem on MMC, dfu_mmc.c buffers up the
> entire file content until the end of the transaction, at which point
> the file is written in one go. This allows writing files larger than
> the USB transfer size (CONFIG_SYS_DFU_DATA_BUF_SIZE); the maximum
> written file size is CONFIG_SYS_DFU_MAX_FILE_SIZE (the size of the
> temporary buffer).
> 
> The current file reading code does not do any buffering, and so limits
> the maximum read file size to the USB transfer size. Enhance the code
> to do the same kind of buffering as the write path, so the same file
> size limits apply.
> 
> Remove the size checking code from dfu_read() since all read paths now
> support larger files than the USB transfer buffer.
> 
> Signed-off-by: Stephen Warren <swarren@nvidia.com>
> ---
>  drivers/dfu/dfu.c     | 11 -----------
>  drivers/dfu/dfu_mmc.c | 27 ++++++++++++++++++++++++++-
>  2 files changed, 26 insertions(+), 12 deletions(-)
> 
> diff --git a/drivers/dfu/dfu.c b/drivers/dfu/dfu.c
> index d85d3f507a7b..d1e465aa7695 100644
> --- a/drivers/dfu/dfu.c
> +++ b/drivers/dfu/dfu.c
> @@ -338,17 +338,6 @@ int dfu_read(struct dfu_entity *dfu, void *buf,
> int size, int blk_seq_num) dfu->r_left = dfu->get_medium_size(dfu);
>  		if (dfu->r_left < 0)
>  			return dfu->r_left;
> -		switch (dfu->layout) {
> -		case DFU_RAW_ADDR:
> -		case DFU_RAM_ADDR:
> -			break;
> -		default:
> -			if (dfu->r_left > dfu_buf_size) {
> -				printf("%s: File too big for
> buffer\n",
> -				       __func__);
> -				return -EOVERFLOW;
> -			}
> -		}
>  
>  		debug("%s: %s %ld [B]\n", __func__, dfu->name,
> dfu->r_left); 
> diff --git a/drivers/dfu/dfu_mmc.c b/drivers/dfu/dfu_mmc.c
> index 2a780f7b5d31..5a9fb4a6e247 100644
> --- a/drivers/dfu/dfu_mmc.c
> +++ b/drivers/dfu/dfu_mmc.c
> @@ -18,6 +18,7 @@
>  
>  static unsigned char *dfu_file_buf;
>  static long dfu_file_buf_len;
> +static long dfu_file_buf_filled;
>  
>  static int mmc_access_part(struct dfu_entity *dfu, struct mmc *mmc,
> int part) {
> @@ -230,9 +231,12 @@ long dfu_get_medium_size_mmc(struct dfu_entity
> *dfu) return dfu->data.mmc.lba_size * dfu->data.mmc.lba_blk_size;
>  	case DFU_FS_FAT:
>  	case DFU_FS_EXT4:
> +		dfu_file_buf_filled = -1;
>  		ret = mmc_file_op(DFU_OP_SIZE, dfu, NULL, &len);
>  		if (ret < 0)
>  			return ret;
> +		if (len > CONFIG_SYS_DFU_MAX_FILE_SIZE)
> +			return -1;
>  		return len;
>  	default:
>  		printf("%s: Layout (%s) not (yet) supported!\n",
> __func__, @@ -241,6 +245,27 @@ long dfu_get_medium_size_mmc(struct
> dfu_entity *dfu) }
>  }
>  
> +static int mmc_file_unbuffer(struct dfu_entity *dfu, u64 offset,
> void *buf,
> +			     long *len)
> +{
> +	int ret;
> +	long file_len;
> +
> +	if (dfu_file_buf_filled == -1) {
> +		ret = mmc_file_op(DFU_OP_READ, dfu, dfu_file_buf,
> &file_len);
> +		if (ret < 0)
> +			return ret;
> +		dfu_file_buf_filled = file_len;
> +	}
> +	if (offset + *len > dfu_file_buf_filled)
> +		return -EINVAL;
> +
> +	/* Add to the current buffer. */
> +	memcpy(buf, dfu_file_buf + offset, *len);
> +
> +	return 0;
> +}
> +
>  int dfu_read_medium_mmc(struct dfu_entity *dfu, u64 offset, void
> *buf, long *len)
>  {
> @@ -252,7 +277,7 @@ int dfu_read_medium_mmc(struct dfu_entity *dfu,
> u64 offset, void *buf, break;
>  	case DFU_FS_FAT:
>  	case DFU_FS_EXT4:
> -		ret = mmc_file_op(DFU_OP_READ, dfu, buf, len);
> +		ret = mmc_file_unbuffer(dfu, offset, buf, len);
>  		break;
>  	default:
>  		printf("%s: Layout (%s) not (yet) supported!\n",
> __func__,

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

Tested-by: Lukasz Majewski <l.majewski@samsung.com>
Test HW: Odroid XU3 - Exynos5433
[DFU Tests]

-- 
Best regards,

Lukasz Majewski

Samsung R&D Institute Poland (SRPOL) | Linux Platform Group