[U-Boot] [PATCH] mtd: cfi: Fix checking status register feature

[York Sun]

On 11/18/2017 11:09 AM, York Sun wrote:
> Commit 72443c7f7d21 ("mtd: cfi: Add support for status register
> polling") added a feature check to determine if status register
> is available for certain flash chips. The "lower software bits"
> register used to determine this feature is not backward compati-
> ble. Older flash chips without this feature has reserved value
> 0xff. Instead of checking "lower software bits" register, use
> CFI primary vendor-specific extended query. Since CFI version
> 1.4, software features can be read from offset 0x53 according to
> document AN201168 from Cypress.
> 
> Signed-off-by: York Sun <york.sun at nxp.com>
> CC: Marek Vasut <marek.vasut at gmail.com>
> ---
> 
>  drivers/mtd/cfi_flash.c | 12 +++++++++---
>  1 file changed, 9 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/mtd/cfi_flash.c b/drivers/mtd/cfi_flash.c
> index 8a5babe..f096e03 100644
> --- a/drivers/mtd/cfi_flash.c
> +++ b/drivers/mtd/cfi_flash.c
> @@ -1694,7 +1694,7 @@ static void cmdset_amd_read_jedec_ids(flash_info_t *info)
>  {
>  	ushort bankId = 0;
>  	uchar  manuId;
> -	uchar  lsbits;
> +	uchar  feature;
>  
>  	flash_write_cmd(info, 0, 0, AMD_CMD_RESET);
>  	flash_unlock_seq(info, 0);
> @@ -1710,8 +1710,14 @@ static void cmdset_amd_read_jedec_ids(flash_info_t *info)
>  	}
>  	info->manufacturer_id = manuId;
>  
> -	lsbits = flash_read_uchar(info, FLASH_OFFSET_LOWER_SW_BITS);
> -	info->sr_supported = lsbits & BIT(0);
> +	debug("info->ext_addr = 0x%x, cfi_version = 0x%x\n",
> +	      info->ext_addr, info->cfi_version);
> +	if (info->ext_addr && info->cfi_version >= 0x3134) {
> +		/* read software feature (at 0x53) */
> +		feature = flash_read_uchar(info, info->ext_addr + 0x13);
> +		debug("feature = 0x%x\n", feature);
> +		info->sr_supported = feature & 0x1;
> +	}
>  
>  	switch (info->chipwidth){
>  	case FLASH_CFI_8BIT:
> 

Mark,

Can you test this patch on your platforms? I verified on my boards.

York