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

[Lukasz Majewski]

Hi Stephen,

> 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)

Those could be defined as static

> +{
> +	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)

Those could be defined as static

> +{
> +	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)

Those could be defined as static

> +{
> +	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);
>  

I've tested it with trats2. It introduces regression with my tests
setup.

I think that it is the highest time to share my test setup for DFU.
Proper patches would be prepared ASAP.

-- 
Best regards,

Lukasz Majewski

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