Re: [PATCH] mtd: spi-nor: spansion: fix writes on S25FS512S

[Alexander Sverdlin <alexander.sverdlin@xxxxxxxxx>]

Hi!

On 20/04/2020 21:13, Sergei Shtylyov wrote:
> Spansion S25FS-S family has an issue in the Basic Flash Parameter Table
> (BFPT): Dword-11 bits 7:4 specify a page size of 512 bytes.  Actually
> this is configurable in the vendor unique register (CR3V) and even the
> factory default setting is to "wrap at 256 bytes", so blindly relying
> on BFPT breaks the page writes on these chips. Add the post-BFPT fixup
> which restores the default page size of 256 bytes -- to properly read
> CR3V this early is quite intrusive and should better be done as a new
> feature; Alexander Sverdlin had the patch doing that:
> 
> https://patchwork.ozlabs.org/project/linux-mtd/patch/20200227123657.26030-1-alexander.sverdlin@xxxxxxxxx/

Right, you patch has a performance impact, but at least unf*cks the chip.

Reviewed-by: Alexander Sverdlin <alexander.sverdlin@xxxxxxxxx>

> Fixes: dfd2b74530e ("mtd: spi-nor: add Spansion S25FS512S ID")
> Signed-off-by: Sergei Shtylyov <sergei.shtylyov@xxxxxxxxxxxxxxxxxx>
> 
> ---
> This patch is against the 'mtd/fixes' branch of the MTD 'linux.git' repo.
> 
>  drivers/mtd/spi-nor/spansion.c |   25 +++++++++++++++++++++++--
>  1 file changed, 23 insertions(+), 2 deletions(-)
> 
> Index: linux/drivers/mtd/spi-nor/spansion.c
> ===================================================================
> --- linux.orig/drivers/mtd/spi-nor/spansion.c
> +++ linux/drivers/mtd/spi-nor/spansion.c
> @@ -8,6 +8,27 @@
>  
>  #include "core.h"
>  
> +static int
> +s25fs_s_post_bfpt_fixups(struct spi_nor *nor,
> +			 const struct sfdp_parameter_header *bfpt_header,
> +			 const struct sfdp_bfpt *bfpt,
> +			 struct spi_nor_flash_parameter *params)
> +{
> +	/*
> +	 * The S25FS-S chip family reports 512-byte pages in BFPT but
> +	 * in reality the write buffer still wraps at the safe default
> +	 * of 256 bytes.  Overwrite the page size advertised by BFPT
> +	 * to get the writes working.
> +	 */
> +	params->page_size = 256;
> +
> +	return 0;
> +}
> +
> +static struct spi_nor_fixups s25fs_s_fixups = {
> +	.post_bfpt = s25fs_s_post_bfpt_fixups,
> +};
> +
>  static const struct flash_info spansion_parts[] = {
>  	/* Spansion/Cypress -- single (large) sector size only, at least
>  	 * for the chips listed here (without boot sectors).
> @@ -30,8 +51,8 @@ static const struct flash_info spansion_
>  			      SPI_NOR_DUAL_READ | SPI_NOR_QUAD_READ |
>  			      SPI_NOR_HAS_LOCK | USE_CLSR) },
>  	{ "s25fs512s",  INFO6(0x010220, 0x4d0081, 256 * 1024, 256,
> -			      SPI_NOR_DUAL_READ | SPI_NOR_QUAD_READ |
> -			      USE_CLSR) },
> +			      SPI_NOR_DUAL_READ | SPI_NOR_QUAD_READ | USE_CLSR)
> +	  .fixups = &s25fs_s_fixups, },
>  	{ "s70fl01gs",  INFO(0x010221, 0x4d00, 256 * 1024, 256, 0) },
>  	{ "s25sl12800", INFO(0x012018, 0x0300, 256 * 1024,  64, 0) },
>  	{ "s25sl12801", INFO(0x012018, 0x0301,  64 * 1024, 256, 0) },
> 

-- 
Best regards,
Alexander Sverdlin.

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