Messages in this thread Patch in this message | | | Date | Sat, 18 Jun 2016 13:31:21 +0200 | From | Boris Brezillon <> | Subject | Re: [PATCH v2 05/15] mtd: nand: add manufacturer specific initialization/detection steps |
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On Sat, 18 Jun 2016 11:23:01 +0200 Richard Weinberger <richard@nod.at> wrote:
> Boris, > > Am 08.06.2016 um 15:00 schrieb Boris Brezillon: > > A lot of NANDs are implementing generic features in a non-generic way, > > or are providing advanced auto-detection logic where the NAND ID bytes > > meaning changes with the NAND generation. > > > > Providing this vendor specific initialization step will allow us to get > > rid of the full ids in the nand_ids table or all the vendor specific > > cases added over the time in the generic NAND ID decoding logic. > > > > Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com> > > --- > > drivers/mtd/nand/nand_base.c | 42 ++++++++++++++++++++++++++++++++---------- > > include/linux/mtd/nand.h | 36 ++++++++++++++++++++++++++++++++++++ > > 2 files changed, 68 insertions(+), 10 deletions(-) > > > > diff --git a/drivers/mtd/nand/nand_base.c b/drivers/mtd/nand/nand_base.c > > index 95e9a8e..0a7d1c6 100644 > > --- a/drivers/mtd/nand/nand_base.c > > +++ b/drivers/mtd/nand/nand_base.c > > @@ -3580,7 +3580,7 @@ static int nand_get_bits_per_cell(u8 cellinfo) > > * chip. The rest of the parameters must be decoded according to generic or > > * manufacturer-specific "extended ID" decoding patterns. > > */ > > -static void nand_decode_ext_id(struct nand_chip *chip) > > +void nand_decode_ext_id(struct nand_chip *chip) > > { > > struct mtd_info *mtd = nand_to_mtd(chip); > > int extid, id_len = chip->id.len; > > @@ -3705,6 +3705,7 @@ static void nand_decode_ext_id(struct nand_chip *chip) > > > > } > > } > > +EXPORT_SYMBOL_GPL(nand_decode_ext_id); > > > > /* > > * Old devices have chip data hardcoded in the device ID table. nand_decode_id > > @@ -3815,7 +3816,7 @@ static int nand_detect(struct nand_chip *chip, struct nand_flash_dev *type) > > { > > struct mtd_info *mtd = nand_to_mtd(chip); > > int busw; > > - int i, maf_idx; > > + int i, maf_idx, ret; > > u8 *id_data = chip->id.data; > > u8 maf_id, dev_id; > > > > @@ -3856,6 +3857,14 @@ static int nand_detect(struct nand_chip *chip, struct nand_flash_dev *type) > > > > chip->id.len = nand_id_len(id_data, 8); > > > > + /* Try to identify manufacturer */ > > + for (maf_idx = 0; nand_manuf_ids[maf_idx].id != 0x0; maf_idx++) { > > + if (nand_manuf_ids[maf_idx].id == maf_id) > > + break; > > + } > > + > > + chip->manufacturer.ops = nand_manuf_ids[maf_idx].ops; > > + > > Instead of checking on every access whether chip->manufacturer.ops is present, just > assign a nop field. > i.e. > > diff --git a/drivers/mtd/nand/nand_base.c b/drivers/mtd/nand/nand_base.c > index 55f3ab8..aadebe7 100644 > --- a/drivers/mtd/nand/nand_base.c > +++ b/drivers/mtd/nand/nand_base.c > @@ -3703,6 +3703,10 @@ static int nand_detect(struct nand_chip *chip, struct nand_flash_dev *type) > > chip->manufacturer.ops = nand_manuf_ids[maf_idx].ops; > > + if (!chip->manufacturer.ops) > + /* assign no operations */ > + chip->manufacturer.ops = nand_manuf_ids[0].ops; > + > if (!type) > type = nand_flash_ids; > > diff --git a/drivers/mtd/nand/nand_ids.c b/drivers/mtd/nand/nand_ids.c > index f1476ff..cdd26af 100644 > --- a/drivers/mtd/nand/nand_ids.c > +++ b/drivers/mtd/nand/nand_ids.c > @@ -173,6 +173,8 @@ extern const struct nand_manufacturer_ops micron_nand_manuf_ops; > extern const struct nand_manufacturer_ops amd_nand_manuf_ops; > extern const struct nand_manufacturer_ops macronix_nand_manuf_ops; > > +static const struct nand_manufacturer_ops no_ops; > + > struct nand_manufacturers nand_manuf_ids[] = { > {NAND_MFR_TOSHIBA, "Toshiba", &toshiba_nand_manuf_ops}, > {NAND_MFR_SAMSUNG, "Samsung", &samsung_nand_manuf_ops}, > @@ -188,7 +190,7 @@ struct nand_manufacturers nand_manuf_ids[] = { > {NAND_MFR_SANDISK, "SanDisk"}, > {NAND_MFR_INTEL, "Intel"}, > {NAND_MFR_ATO, "ATO"}, > - {0x0, "Unknown"} > + {0x0, "Unknown", &no_ops} > }; > > EXPORT_SYMBOL(nand_manuf_ids); >
Sorry, but I don't see any added value in adding this no_ops instance. The NULL value is supposed to represent no_ops. That's not like this path was critical: it's only call once during NAND initialization.
How about adding the following helpers instead:
static inline bool nand_has_manufacturer_ops(struct nand_chip * chip) { return chip->manufacturer.ops != NULL; }
static inline void nand_manufacturer_detect(struct nand_chip * chip) { if (!chip->manufacturer.ops || chip->manufacturer.ops->detect) return;
chip->manufacturer.ops->detect(chip); }
static inline int nand_manufacturer_init(struct nand_chip * chip) { if (!chip->manufacturer.ops || chip->manufacturer.ops->init) return 0;
return chip->manufacturer.ops->init(chip); }
> > > if (!type) > > type = nand_flash_ids; > > > > @@ -3903,8 +3912,14 @@ static int nand_detect(struct nand_chip *chip, struct nand_flash_dev *type) > > chip->chipsize = (uint64_t)type->chipsize << 20; > > > > if (!type->pagesize) { > > - /* Decode parameters from extended ID */ > > - nand_decode_ext_id(chip); > > + /* > > + * Try manufacturer detection if available and use > > + * nand_decode_ext_id() otherwise. > > + */ > > + if (chip->manufacturer.ops->detect) > > You need to check here for chip->manufacturer.ops first.
Correct.
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