[U-Boot] [PATCH 1/5] mtd: spi-nor: fix page program issue when using spi-mem driver

[Vignesh Raghavendra]

Hi,

+Jagan

On 26/04/19 2:52 PM, Weijie Gao wrote:
> Some SPI controllers can't write nor->page_size bytes in a single step
> because their TX FIFO is too small, but when that happens we should
> make sure a WRITE_EN command before each write access and READ_SR command
> after each write access is issued.
> 
> We should allow nor->write() to return a size that is smaller than the
> requested write size to gracefully handle this case.
> 
> Also, the spi_nor_write_data() should return the actual number of bytes
> that were written during the spi_mem_exec_op() operation.
> 
> This patch is a combination of two commits backported from kernel:
> 
>   commit 630d6bd8a3b4 ("mtd: spi-nor: Support controllers with limit ...")
>   commit 3baa8ec88c2f ("mtd: devices: m25p80: Make sure WRITE_EN is ...")
> 
> Cc: Vignesh R <vigneshr at ti.com>
> Signed-off-by: Weijie Gao <weijie.gao at mediatek.com>

Thanks for the patch.

Acked-by: Vignesh R <vigneshr at ti.com>

Jagan

This patch fixes a regression wrt writing to flash on two platforms.
Could you consider queuing this patch for next -rc?

Regards
Vignesh

> ---
>  drivers/mtd/spi/spi-nor-core.c | 27 ++++++++-------------------
>  1 file changed, 8 insertions(+), 19 deletions(-)
> 
> diff --git a/drivers/mtd/spi/spi-nor-core.c b/drivers/mtd/spi/spi-nor-core.c
> index c4e2f6a..1acff74 100644
> --- a/drivers/mtd/spi/spi-nor-core.c
> +++ b/drivers/mtd/spi/spi-nor-core.c
> @@ -116,7 +116,6 @@ static ssize_t spi_nor_write_data(struct spi_nor *nor, loff_t to, size_t len,
>  				   SPI_MEM_OP_ADDR(nor->addr_width, to, 1),
>  				   SPI_MEM_OP_NO_DUMMY,
>  				   SPI_MEM_OP_DATA_OUT(len, buf, 1));
> -	size_t remaining = len;
>  	int ret;
>  
>  	/* get transfer protocols. */
> @@ -127,22 +126,16 @@ static ssize_t spi_nor_write_data(struct spi_nor *nor, loff_t to, size_t len,
>  	if (nor->program_opcode == SPINOR_OP_AAI_WP && nor->sst_write_second)
>  		op.addr.nbytes = 0;
>  
> -	while (remaining) {
> -		op.data.nbytes = remaining < UINT_MAX ? remaining : UINT_MAX;
> -		ret = spi_mem_adjust_op_size(nor->spi, &op);
> -		if (ret)
> -			return ret;
> -
> -		ret = spi_mem_exec_op(nor->spi, &op);
> -		if (ret)
> -			return ret;
> +	ret = spi_mem_adjust_op_size(nor->spi, &op);
> +	if (ret)
> +		return ret;
> +	op.data.nbytes = len < op.data.nbytes ? len : op.data.nbytes;
>  
> -		op.addr.val += op.data.nbytes;
> -		remaining -= op.data.nbytes;
> -		op.data.buf.out += op.data.nbytes;
> -	}
> +	ret = spi_mem_exec_op(nor->spi, &op);
> +	if (ret)
> +		return ret;
>  
> -	return len;
> +	return op.data.nbytes;
>  }
>  
>  /*
> @@ -1101,10 +1094,6 @@ static int spi_nor_write(struct mtd_info *mtd, loff_t to, size_t len,
>  			goto write_err;
>  		*retlen += written;
>  		i += written;
> -		if (written != page_remain) {
> -			ret = -EIO;
> -			goto write_err;
> -		}
>  	}
>  
>  write_err:
> 

-- 
Regards
Vignesh