diff mbox series

[1/2] mtd: spinand: Add support for 5-byte IDs

Message ID 20240125200108.24374-2-ezra@easyb.ch
State Accepted
Headers show
Series mtd: spinand: Resolve GigaDevice/ESMT ID clash | expand

Commit Message

Ezra Buehler Jan. 25, 2024, 8:01 p.m. UTC 
From: Ezra Buehler <ezra.buehler@husqvarnagroup.com>

E.g. ESMT chips will return an identification code with a length of 5
bytes. In order to prevent ambiguity, flash chips would actually need to
return IDs that are up to 17 or more bytes long due to JEDEC's
continuation scheme. I understand that if a manufacturer ID is located
in bank N of JEDEC's database (there are currently 16 banks), N - 1
continuation codes (7Fh) need to be added to the identification code
(comprising of manufacturer ID and device ID). However, most flash chip
manufacturers don't seem to implement this (correctly).

Signed-off-by: Ezra Buehler <ezra.buehler@husqvarnagroup.com>
---
 include/linux/mtd/spinand.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

Comments

Martin Kurbanov Jan. 26, 2024, 6:46 p.m. UTC | #1 
On 25.01.2024 23:01, Ezra Buehler wrote:
> From: Ezra Buehler <ezra.buehler@husqvarnagroup.com>
> 
> E.g. ESMT chips will return an identification code with a length of 5
> bytes. In order to prevent ambiguity, flash chips would actually need to
> return IDs that are up to 17 or more bytes long due to JEDEC's
> continuation scheme. I understand that if a manufacturer ID is located
> in bank N of JEDEC's database (there are currently 16 banks), N - 1
> continuation codes (7Fh) need to be added to the identification code
> (comprising of manufacturer ID and device ID). However, most flash chip
> manufacturers don't seem to implement this (correctly).
> 
> Signed-off-by: Ezra Buehler <ezra.buehler@husqvarnagroup.com>

Tested for F50L1G41LB

Reviewed-by: Martin Kurbanov <mmkurbanov@salutedevices.com>
Tested-by: Martin Kurbanov <mmkurbanov@salutedevices.com>

> ---
>  include/linux/mtd/spinand.h | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/include/linux/mtd/spinand.h b/include/linux/mtd/spinand.h
> index badb4c1ac079..5c19ead60499 100644
> --- a/include/linux/mtd/spinand.h
> +++ b/include/linux/mtd/spinand.h
> @@ -169,7 +169,7 @@
>  struct spinand_op;
>  struct spinand_device;
>  
> -#define SPINAND_MAX_ID_LEN	4
> +#define SPINAND_MAX_ID_LEN	5
>  /*
>   * For erase, write and read operation, we got the following timings :
>   * tBERS (erase) 1ms to 4ms
Miquel Raynal Feb. 5, 2024, 2:28 p.m. UTC | #2 
On Thu, 2024-01-25 at 20:01:07 UTC, Ezra Buehler wrote:
> From: Ezra Buehler <ezra.buehler@husqvarnagroup.com>
> 
> E.g. ESMT chips will return an identification code with a length of 5
> bytes. In order to prevent ambiguity, flash chips would actually need to
> return IDs that are up to 17 or more bytes long due to JEDEC's
> continuation scheme. I understand that if a manufacturer ID is located
> in bank N of JEDEC's database (there are currently 16 banks), N - 1
> continuation codes (7Fh) need to be added to the identification code
> (comprising of manufacturer ID and device ID). However, most flash chip
> manufacturers don't seem to implement this (correctly).
> 
> Signed-off-by: Ezra Buehler <ezra.buehler@husqvarnagroup.com>
> Reviewed-by: Martin Kurbanov <mmkurbanov@salutedevices.com>
> Tested-by: Martin Kurbanov <mmkurbanov@salutedevices.com>

Applied to https://git.kernel.org/pub/scm/linux/kernel/git/mtd/linux.git nand/next, thanks.

Miquel
diff mbox series

Patch

diff --git a/include/linux/mtd/spinand.h b/include/linux/mtd/spinand.h
index badb4c1ac079..5c19ead60499 100644
--- a/include/linux/mtd/spinand.h
+++ b/include/linux/mtd/spinand.h
@@ -169,7 +169,7 @@ 
 struct spinand_op;
 struct spinand_device;
 
-#define SPINAND_MAX_ID_LEN	4
+#define SPINAND_MAX_ID_LEN	5
 /*
  * For erase, write and read operation, we got the following timings :
  * tBERS (erase) 1ms to 4ms