RE: [PATCHv2] mmc-utils: Fix 4k sector size block count in FFU

[Avri Altman <Avri.Altman@wdc.com>]

> FFU used the wrong assumption, that CMD23 work in
> 4k sector chunks when setting the block count.
> Instead the CMD23 block count argument just needs
> to be a multiple of 8, which the fw_size is anyway.
> 
> Fixes: 89cd01ed865a (mmc_utils: add ffu support)
> Signed-off-by: Christian Loehle <cloehle@hyperstone.com>
Reviewed-by: Avri Altman <avri.altman@wdc.com>

Thanks,
Avri
> ---
>  mmc_cmds.c | 15 ++++++++-------
>  1 file changed, 8 insertions(+), 7 deletions(-)
> 
> diff --git a/mmc_cmds.c b/mmc_cmds.c
> index bb0f022..12b7802 100644
> --- a/mmc_cmds.c
> +++ b/mmc_cmds.c
> @@ -2768,7 +2768,6 @@ int do_ffu(int nargs, char **argv)
>         ssize_t chunk_size;
>         char *device;
>         struct mmc_ioc_multi_cmd *multi_cmd = NULL;
> -       __u32 blocks = 1;
> 
>         if (nargs != 3) {
>                 fprintf(stderr, "Usage: ffu <image name> </path/to/mmcblkX> \n");
> @@ -2826,15 +2825,13 @@ int do_ffu(int nargs, char **argv)
>                 goto out;
>         }
> 
> +       /* ensure fw is multiple of native sector size */
>         sect_size = (ext_csd[EXT_CSD_DATA_SECTOR_SIZE] == 0) ? 512 : 4096;
>         if (fw_size % sect_size) {
>                 fprintf(stderr, "Firmware data size (%jd) is not aligned!\n",
> (intmax_t)fw_size);
>                 goto out;
>         }
> 
> -       /* calculate required fw blocks for CMD25 */
> -       blocks = fw_size / sect_size;
> -
>         /* set CMD ARG */
>         arg = ext_csd[EXT_CSD_FFU_ARG_0] |
>                 ext_csd[EXT_CSD_FFU_ARG_1] << 8 |
> @@ -2857,13 +2854,17 @@ int do_ffu(int nargs, char **argv)
> 
>         /* send block count */
>         multi_cmd->cmds[1].opcode = MMC_SET_BLOCK_COUNT;
> -       multi_cmd->cmds[1].arg = blocks;
> +       multi_cmd->cmds[1].arg = fw_size / 512;
>         multi_cmd->cmds[1].flags = MMC_RSP_SPI_R1 | MMC_RSP_R1 |
> MMC_CMD_AC;
> 
>         /* send image chunk */
>         multi_cmd->cmds[2].opcode = MMC_WRITE_MULTIPLE_BLOCK;
> -       multi_cmd->cmds[2].blksz = sect_size;
> -       multi_cmd->cmds[2].blocks = blocks;
> +       /*
> +        * blksz and blocks essentially do not matter, as long as the product
> +        * is fw_size, but some hosts don't handle larger blksz well.
> +        */
> +       multi_cmd->cmds[2].blksz = 512;
> +       multi_cmd->cmds[2].blocks = fw_size / 512;
>         multi_cmd->cmds[2].arg = arg;
>         multi_cmd->cmds[2].flags = MMC_RSP_SPI_R1 | MMC_RSP_R1 |
> MMC_CMD_ADTC;
>         multi_cmd->cmds[2].write_flag = 1;
> --
> 2.36.1
> 
> Hyperstone GmbH | Reichenaustr. 39a  | 78467 Konstanz
> Managing Director: Dr. Jan Peter Berns.
> Commercial register of local courts: Freiburg HRB381782