[PATCH v2] mtd: spi-nor: wait until lock/unlock operations are ready

[Brian Norris]

On Mon, Dec 28, 2015 at 05:54:51PM -0300, Ezequiel Garcia wrote:
> On Micron and Numonyx devices, the status register write command
> (WRSR), raises a work-in-progress bit (WIP) on the status register.
> The datasheets for these devices specify that while the status
> register write is in progress, the status register WIP bit can still
> be read to check the end of the operation.
> 
> This commit adds a wait_till_ready call on lock/unlock operations,
> only for these manufacturers. This is needed to prevent applications

Edited the above sentence, since you're not doing this "only for these
manufacturers"; you're doing it for all that support lock/unlock.
Instead, it'll read:

  "This commit adds a wait_till_ready call on lock/unlock operations,
  which is required for Micron and Numonyx but should be harmless for
  others."

With that, applied to l2-mtd.git

Brian

> from issuing erase or program operations before the unlock operation
> is completed.
> 
> Reported-by: Stas Sergeev <stsp at list.ru>
> Signed-off-by: Ezequiel Garcia <ezequiel at vanguardiasur.com.ar>
> ---
> Changes from v1:
>  * Simplify style by tail calling spi_nor_wait_till_ready
>  
>  drivers/mtd/spi-nor/spi-nor.c | 12 ++++++++++--
>  1 file changed, 10 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/mtd/spi-nor/spi-nor.c b/drivers/mtd/spi-nor/spi-nor.c
> index 7e5051e604b0..835a010d9339 100644
> --- a/drivers/mtd/spi-nor/spi-nor.c
> +++ b/drivers/mtd/spi-nor/spi-nor.c
> @@ -481,6 +481,7 @@ static int stm_lock(struct spi_nor *nor, loff_t ofs, uint64_t len)
>  	int status_old, status_new;
>  	u8 mask = SR_BP2 | SR_BP1 | SR_BP0;
>  	u8 shift = ffs(mask) - 1, pow, val;
> +	int ret;
>  
>  	status_old = read_sr(nor);
>  	if (status_old < 0)
> @@ -519,7 +520,10 @@ static int stm_lock(struct spi_nor *nor, loff_t ofs, uint64_t len)
>  		return -EINVAL;
>  
>  	write_enable(nor);
> -	return write_sr(nor, status_new);
> +	ret = write_sr(nor, status_new);
> +	if (ret)
> +		return ret;
> +	return spi_nor_wait_till_ready(nor);
>  }
>  
>  /*
> @@ -533,6 +537,7 @@ static int stm_unlock(struct spi_nor *nor, loff_t ofs, uint64_t len)
>  	int status_old, status_new;
>  	u8 mask = SR_BP2 | SR_BP1 | SR_BP0;
>  	u8 shift = ffs(mask) - 1, pow, val;
> +	int ret;
>  
>  	status_old = read_sr(nor);
>  	if (status_old < 0)
> @@ -569,7 +574,10 @@ static int stm_unlock(struct spi_nor *nor, loff_t ofs, uint64_t len)
>  		return -EINVAL;
>  
>  	write_enable(nor);
> -	return write_sr(nor, status_new);
> +	ret = write_sr(nor, status_new);
> +	if (ret)
> +		return ret;
> +	return spi_nor_wait_till_ready(nor);
>  }
>  
>  /*
> -- 
> 2.6.4
>