[PATCH v2] mtd: spi-nor: sfdp: Fix index value for SCCR dwords

[Tudor.Ambarus at microchip.com]

Hi, Takahiro,

On 9/12/22 08:13, tkuw584924 at gmail.com wrote:
> EXTERNAL EMAIL: Do not click links or open attachments unless you know the content is safe
> 
> From: Takahiro Kuwano <Takahiro.Kuwano at infineon.com>
> 
> Array index for SCCR 22th DOWRD should be 21.
> 
> Fixes: 981a8d60e01f ("mtd: spi-nor: Parse SFDP SCCR Map")
> Signed-off-by: Takahiro Kuwano <Takahiro.Kuwano at infineon.com>
> ---
> v2: Add Fixes tag.
> 
>  drivers/mtd/spi-nor/sfdp.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/mtd/spi-nor/sfdp.c b/drivers/mtd/spi-nor/sfdp.c
> index 2257f1b4c2e2..681e5e78724c 100644
> --- a/drivers/mtd/spi-nor/sfdp.c
> +++ b/drivers/mtd/spi-nor/sfdp.c
> @@ -1222,7 +1222,7 @@ static int spi_nor_parse_sccr(struct spi_nor *nor,
> 
>         le32_to_cpu_array(dwords, sccr_header->length);
> 
> -       if (FIELD_GET(SCCR_DWORD22_OCTAL_DTR_EN_VOLATILE, dwords[22]))
> +       if (FIELD_GET(SCCR_DWORD22_OCTAL_DTR_EN_VOLATILE, dwords[21]))

Would such a change work?
diff --git a/drivers/mtd/spi-nor/sfdp.h b/drivers/mtd/spi-nor/sfdp.h
index bbf80d2990ab..e83d9bd89066 100644
--- a/drivers/mtd/spi-nor/sfdp.h
+++ b/drivers/mtd/spi-nor/sfdp.h
@@ -19,7 +19,7 @@
  * JESD216 rev D defines a Basic Flash Parameter Table of 20 DWORDs.
  * They are indexed from 1 but C arrays are indexed from 0.
  */
-#define BFPT_DWORD(i)          ((i) - 1)
+#define SFDP_DWORD(i)          ((i) - 1)


and use:
+       if (FIELD_GET(SCCR_DWORD22_OCTAL_DTR_EN_VOLATILE, dwords[SFDP_DWORD(22)]))

and dwords may be renamed to sccrm, from "Status, Control and Configuration Register Map",
so:
+       if (FIELD_GET(SCCRM_DWORD22_OCTAL_DTR_EN_VOLATILE, sccrm[SFDP_DWORD(22)]))

But you'll have to check that all the tables from the latest jesd216 (e version I guess)
use the same kind of indexing. Let me know if you'd like to pursue my suggestion instead.

-- 
Cheers,
ta