lkml.org 
[lkml]   [2022]   [Jul]   [19]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
From
SubjectRe: [PATCH 1/2] mtd: spi-nor: introduce SNOR_ID3()
Date
On 5/10/22 17:02, Michael Walle wrote:

Hi!

> EXTERNAL EMAIL: Do not click links or open attachments unless you know the content is safe
>
> Up until now, flashes were defined by specifying the JEDEC ID, the
> sector size and the number of sectors. This can be read by parsing the
> SFDP, we don't have to specify it. Thus provide a new macro SNOR_ID3()
> which just takes the JEDEC ID and implicitly set .parse_sfdp = true. All
> new flashes which have SFDP should use this macro.

I like the idea, but you need to refine it a bit.
Your assumptions are true only for flashes that are compliant with SFDP revB or
later because params->page_size is initialized by querying BFPT DWORD 11. I think
it would be good to specify this in the comment section. Also, I think you introduce
a bug in spi_nor_select_erase() when CONFIG_MTD_SPI_NOR_USE_4K_SECTORS is not
selected. wanted_size will be zero, will you select an invalid erase type?
Would you please resubmit?

Thanks,
ta

>
> Signed-off-by: Michael Walle <michael@walle.cc>
> ---
> drivers/mtd/spi-nor/core.c | 7 +++++--
> drivers/mtd/spi-nor/core.h | 9 +++++++++
> 2 files changed, 14 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/mtd/spi-nor/core.c b/drivers/mtd/spi-nor/core.c
> index 402b37cdbcea..29329ed0a934 100644
> --- a/drivers/mtd/spi-nor/core.c
> +++ b/drivers/mtd/spi-nor/core.c
> @@ -2104,8 +2104,11 @@ static int spi_nor_select_pp(struct spi_nor *nor,
> * spi_nor_select_uniform_erase() - select optimum uniform erase type
> * @map: the erase map of the SPI NOR
> * @wanted_size: the erase type size to search for. Contains the value of
> - * info->sector_size or of the "small sector" size in case
> - * CONFIG_MTD_SPI_NOR_USE_4K_SECTORS is defined.
> + * info->sector_size, the "small sector" size in case
> + * CONFIG_MTD_SPI_NOR_USE_4K_SECTORS is defined or 0 if
> + * there is no information about the sector size. The
> + * latter is the case if the flash parameters are parsed
> + * solely by SFDP.
> *
> * Once the optimum uniform sector erase command is found, disable all the
> * other.
> diff --git a/drivers/mtd/spi-nor/core.h b/drivers/mtd/spi-nor/core.h
> index 61886868cd02..fab3038c4f4a 100644
> --- a/drivers/mtd/spi-nor/core.h
> +++ b/drivers/mtd/spi-nor/core.h
> @@ -563,6 +563,15 @@ struct flash_info {
> .n_regions = (_n_regions), \
> },
>
> +#define SNOR_ID3(_jedec_id) \
> + .id = { \
> + ((_jedec_id) >> 16) & 0xff, \
> + ((_jedec_id) >> 8) & 0xff, \
> + (_jedec_id) & 0xff, \
> + }, \
> + .id_len = 3, \
> + .parse_sfdp = true, \
> +
> #define PARSE_SFDP \
> .parse_sfdp = true, \
>
> --
> 2.30.2
>

\
 
 \ /
  Last update: 2022-07-19 07:58    [W:0.208 / U:0.604 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site