[PATCH v3 2/2] mtd: spi: nor: force mtd name to "nor%d"

[Marek Vasut]

On 9/17/21 3:06 PM, Patrick DELAUNAY wrote:
> Hi Marek,
> 
>  > Marek VasutSept. 16, 2021, 5:27 p.m. UTC | #3
>  > On 9/16/21 4:01 PM, Patrick Delaunay wrote:
> 
>  > [...]
> 
>  > > @@ -3664,6 +3666,11 @@ int spi_nor_scan(struct spi_nor *nor)
>  > >       struct mtd_info *mtd = &nor->mtd;
>  > >       struct spi_slave *spi = nor->spi;
>  > >       int ret;
>  > > +    int cfi_mtd_nb = 0;
>  > > +
>  > > +#ifdef CONFIG_SYS_MAX_FLASH_BANKS
>  > > +    cfi_mtd_nb = CONFIG_SYS_MAX_FLASH_BANKS;
>  > > +#endif
> 
>  > Are we covering all the NORs (HF and co.) with this ?
> 
> 
> Yes, except if I miss something
> 
> 
> any NOR (including hyperflash) wich use the CFI interface / 
> CONFIG_FLASH_CFI_MTD
> 
> define the the 'nor%d' name with the calling stack:

Yes

> initr_flash()
> 
> => flash_init()
> 
> ==> cfi_flash_init_dm()
> 
> ==> cfi_mtd_init()   "nor%d" wich use loop on CONFIG_SYS_MAX_FLASH_BANKS
> 
> 
> I have only one concern today...
> 
> 
> if one cfi bank is missing (not activated in DT by example)
> 
> and CONFIG_SYS_MAX_FLASH_BANKS_DETECT is not activated
> 
> some holes can be done in index
> 
> 
> example:
> 
> with CONFIG_SYS_MAX_FLASH_BANKS = 2 but with only one NOR on the board
> 
> => "nor1" is absent and we have only 2 MTD device named "nor"
> 
> - "nor0" => NOR or HF, first CFI bank
> 
> - "nor2" => SPI-NOR (first)
> 
> 
> but I don't think that it is blocking

Wasn't the old behavior exactly the same anyway ?

>  > >       /* Reset SPI protocol for all commands. */
>  > >       nor->reg_proto = SNOR_PROTO_1_1_1;
>  > > @@ -3715,8 +3722,10 @@ int spi_nor_scan(struct spi_nor *nor)
>  > >       if (ret)
>  > >           return ret;
>  > >
>  > > -    if (!mtd->name)
>  > > -        mtd->name = info->name;
>  > > +    if (!mtd->name) {
>  > > +        sprintf(nor->mtd_name, "nor%d",  cfi_mtd_nb + 
> dev_seq(nor->dev));
>  > > +        mtd->name = nor->mtd_name;
>  > > +    }
>  > >       mtd->dev = nor->dev;
>  > >       mtd->priv = nor;
>  > >       mtd->type = MTD_NORFLASH;
>  > > @@ -3821,7 +3830,7 @@ int spi_nor_scan(struct spi_nor *nor)
>  > >
>  > >       nor->rdsr_dummy = params.rdsr_dummy;
>  > >       nor->rdsr_addr_nbytes = params.rdsr_addr_nbytes;
>  > > -    nor->name = mtd->name;
>  > > +    nor->name = info->name;
>  > >       nor->size = mtd->size;
>  > >       nor->erase_size = mtd->erasesize;
>  > >       nor->sector_size = mtd->erasesize;
>  > > diff --git a/include/linux/mtd/spi-nor.h b/include/linux/mtd/spi-nor.h
>  > > index 7ddc4ba2bf..8c3d5032e3 100644
>  > > --- a/include/linux/mtd/spi-nor.h
>  > > +++ b/include/linux/mtd/spi-nor.h
>  > > @@ -561,6 +561,7 @@ struct spi_nor {
>  > >       int (*ready)(struct spi_nor *nor);
>  > >
>  > >       void *priv;
>  > > +    char mtd_name[10];
> 
>  > should be 14, because nor%d\0 can be up to 14 bytes long.
> 
> normally DM_MAX_SEQ = 999 (but never used)
> 
> but Ok with you for 14 with "nor" = 3 + "%d" = 10 for max u32 value + 
> "/0" = 1
> 
> 
> for cfi_mtd_names => 16 byte used with "nor%d"
> 
>      static char cfi_mtd_names[CFI_MAX_FLASH_BANKS][16];
> 
> for nand => 8 bytes (./drivers/mtd/nand/raw/nand.c:59)
> 
>      static char dev_name[CONFIG_SYS_MAX_NAND_DEVICE][8];
> 
> for spi-nand => 20 bytes (drivers/mtd/nand/spi/core.c:1169)
> 
>      mtd->name = malloc(20);

Maybe we need a macro for this length of DM seq string which we could 
use in these embedded array cases.