[PATCH 9/9] mtd: nand: detect Samsung K9GBG08U0A, K9GAG08U0F ID
Marek Vasut
marex at denx.de
Sat Oct 6 23:29:51 EDT 2012
Dear Brian Norris,
> Hi Marek,
>
> On Thu, Oct 4, 2012 at 6:37 PM, Marek Vasut <marex at denx.de> wrote:
> > This breaks my board with K9F2G08 part:
> >
> > [ 0.860000] NAND device: Manufacturer ID: 0xec, Chip ID: 0xda (Samsung
> > NAND 256MiB 3,3V 8-bit), page size: 2048, OOB size: 64
>
> Thanks for the report. I really appreciate the testing! Exactly which
> part is this, and what is the full 8-byte ID? For instance, I can
> reproduce this on K9F2G08U0B, with ID EC DA 10 95 44 00 EC DA.
Yep, that's it ...
ec da 10 95 44 00 ec da
> >> diff --git a/drivers/mtd/nand/nand_base.c b/drivers/mtd/nand/nand_base.c
> >> index 7e93d0d..bcb58ce 100644
> >> --- a/drivers/mtd/nand/nand_base.c
> >> +++ b/drivers/mtd/nand/nand_base.c
> >> @@ -2939,19 +2939,18 @@ static void nand_decode_ext_id(struct mtd_info
> >> *mtd, struct nand_chip *chip, /*
> >>
> >> * Field definitions are in the following datasheets:
> >> * Old style (4,5 byte ID): Samsung K9GAG08U0M (p.32)
> >>
> >> - * New style (6 byte ID): Samsung K9GBG08U0M (p.40)
> >> + * New style (6 byte ID): Samsung K9GAG08U0F (p.44)
> >>
> >> * Hynix MLC (6 byte ID): Hynix H27UBG8T2B (p.22)
> >> *
> >> * Check for ID length, cell type, and Hynix/Samsung ID to decide
> >> what * to do.
> >> */
> >>
> >> - if (id_len == 6 && id_data[0] == NAND_MFR_SAMSUNG &&
> >> - (chip->cellinfo & NAND_CI_CELLTYPE_MSK)) {
> >> + if (id_len == 6 && id_data[0] == NAND_MFR_SAMSUNG) {
> >
> > [...]
> >
> > I believe the above hunk is wrong, reverting it fixes the problem.
>
> Yeah, that is one fix. But my real issue is in the ID length, not SLC
> vs. MLC. Its datasheet *says* it has a 5-byte ID, but it actually
> wraps around at the 6-byte mark (i.e., EC DA 10 95 44 00 EC DA ...) so
> its ID length appears as 6. Now, the above hunk is intentional, since
> I found Samsung SLC NAND with 6-byte ID which follow this same
> pattern. And I don't have any recorded Samsung 6-byte ID SLC who
> *don't* follow this pattern. See the following doc, plus I have more
> NAND data that should be updated here sometime:
>
> http://www.linux-mtd.infradead.org/nand-data/nanddata.html
Nice!
> Anyway, according to my data, the problem is actually in this hunk in patch
> 6:
>
> mtd: nand: add generic READ ID length calculation functions
>
> - if (id_data[0] == id_data[6] && id_data[1] == id_data[7] &&
> - id_data[0] == NAND_MFR_SAMSUNG &&
> - (chip->cellinfo & NAND_CI_CELLTYPE_MSK) &&
> - id_data[5] != 0x00) {
> + if (id_len == 6 && id_data[0] == NAND_MFR_SAMSUNG &&
> + (chip->cellinfo & NAND_CI_CELLTYPE_MSK)) {
>
> Notice that I dropped the 'id_data[5] != 0x00' check. So I think if I
> squash the following diff (probably mangled) into the series, this
> solves your problems and mine. Can you test?
Yes, that's a good solution.
Tested-by: Marek Vasut <marex at denx.de>
> If it works, I'll probably resend this diff with a full, proper
> explanation (and Tested-by credit), or else I can send a v2 of patches
> 6 and 9. (It's up to Artem, which form he'd rather maintain in his
> tree.)
>
> Thanks,
> Brian
>
> ---
> diff --git a/drivers/mtd/nand/nand_base.c b/drivers/mtd/nand/nand_base.c
> index ec6841d..fa1ae76 100644
> --- a/drivers/mtd/nand/nand_base.c
> +++ b/drivers/mtd/nand/nand_base.c
> @@ -2989,7 +2989,8 @@ static void nand_decode_ext_id(struct mtd_info
> *mtd, struct nand_chip *chip,
> * Check for ID length, cell type, and Hynix/Samsung ID to decide what
> * to do.
> */
> - if (id_len == 6 && id_data[0] == NAND_MFR_SAMSUNG) {
> + if (id_len == 6 && id_data[0] == NAND_MFR_SAMSUNG &&
> + id_data[5] != 0x00) {
> /* Calc pagesize */
> mtd->writesize = 2048 << (extid & 0x03);
> extid >>= 2;
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