Re: [PATCH v2 4/7] mtd: spi-nor: Split spi_nor_init_params()

[Tudor.Ambarus]

On 08/25/2019 03:03 PM, Boris Brezillon wrote:
> External E-Mail
> 
> 
> On Sat, 24 Aug 2019 12:00:43 +0000
> <Tudor.Ambarus@xxxxxxxxxxxxx> wrote:
> 
>> From: Tudor Ambarus <tudor.ambarus@xxxxxxxxxxxxx>
>>
>> Add functions to delimit what the chunks of code do:
>>
>> static void spi_nor_init_params()
>> {
>> 	spi_nor_legacy_init_params()
>> 	spi_nor_manufacturer_init_params()
>> 	spi_nor_sfdp_init_params()
>> }
>>
>> Add descriptions to all methods.
>>
>> spi_nor_init_params() becomes of type void, as all its children
>> return void.
>>
>> Signed-off-by: Tudor Ambarus <tudor.ambarus@xxxxxxxxxxxxx>
>> ---
>>  drivers/mtd/spi-nor/spi-nor.c | 83 ++++++++++++++++++++++++++++++++-----------
>>  1 file changed, 63 insertions(+), 20 deletions(-)
>>
>> diff --git a/drivers/mtd/spi-nor/spi-nor.c b/drivers/mtd/spi-nor/spi-nor.c
>> index c9514dfd7d6d..93424f914159 100644
>> --- a/drivers/mtd/spi-nor/spi-nor.c
>> +++ b/drivers/mtd/spi-nor/spi-nor.c
>> @@ -4186,7 +4186,34 @@ static void spi_nor_manufacturer_init_params(struct spi_nor *nor)
>>  		nor->info->fixups->default_init(nor);
>>  }
>>  
>> -static int spi_nor_init_params(struct spi_nor *nor)
>> +/**
>> + * spi_nor_sfdp_init_params() - Initialize the flash's parameters and settings
>> + * based on JESD216 SFDP standard.
>> + * @nor:	pointer to a 'struct spi-nor'.
>> + *
>> + * The method has a roll-back mechanism: in case the SFDP parsing fails, the
>> + * legacy flash parameters and settings will be restored.
>> + */
>> +static void spi_nor_sfdp_init_params(struct spi_nor *nor)
>> +{
>> +	struct spi_nor_flash_parameter sfdp_params;
>> +
>> +	memcpy(&sfdp_params, &nor->params, sizeof(sfdp_params));
>> +
>> +	if (spi_nor_parse_sfdp(nor, &sfdp_params)) {
>> +		nor->addr_width = 0;
>> +		nor->flags &= ~SNOR_F_4B_OPCODES;
>> +	} else {
>> +		memcpy(&nor->params, &sfdp_params, sizeof(nor->params));
>> +	}
>> +}
>> +
>> +/**
>> + * spi_nor_legacy_init_params() - Initialize the flash's parameters and settings
>> + * based on nor->info data.
>> + * @nor:	pointer to a 'struct spi-nor'.
>> + */
>> +static void spi_nor_legacy_init_params(struct spi_nor *nor)
> 
> Nitpick: hm, I'm not a big fan of the 'legacy' term here as I'm not sure
> it reflects the reality. I guess this function will stay around, and
> even new NORs are not guaranteed to provide SFDP tables. How about
> spi_nor_set_default_params() or spi_nor_info_init_params()?

I can rename it to spi_nor_info_init_params() to be in sync with
                   spi_nor_manufacturer_init_params() and
                   spi_nor_sfdp_init_params()

or I can rename all to:
spi_nor_set_params()
spi_nor_set_default_params()
spi_nor_set_manufacturer_params()
spi_nor_set_sfdp_params()

Both are ok, but the second option seems better. What would you choose?

> 
> That's just a suggestion, so here is my
> 
> Reviewed-by: Boris Brezillon <boris.brezillon@xxxxxxxxxxxxx>
> 
> in case you want to ignore it.
> 
>>  {
>>  	struct spi_nor_flash_parameter *params = &nor->params;
>>  	struct spi_nor_erase_map *map = &params->erase_map;
>> @@ -4260,25 +4287,43 @@ static int spi_nor_init_params(struct spi_nor *nor)
>>  	spi_nor_set_erase_type(&map->erase_type[i], info->sector_size,
>>  			       SPINOR_OP_SE);
>>  	spi_nor_init_uniform_erase_map(map, erase_mask, params->size);
>> +}
>>  
>> +/**
>> + * spi_nor_init_params() - Initialize the flash's parameters and settings.
>> + * @nor:	pointer to a 'struct spi-nor'.
>> + *
>> + * The flash parameters and settings are initialized based on a sequence of
>> + * calls that are ordered by priority:
>> + *
>> + * 1/ Legacy flash parameters initialization. The initializations are done
>> + *    based on nor->info data:
>> + *		spi_nor_legacy_init_params()
>> + *
>> + * which can be overwritten by:
>> + * 2/ Manufacturer flash parameters initialization. The initializations are
>> + *    done based on MFR register, or when the decisions can not be done solely
>> + *    based on MFR, by using specific flash_info tweeks, ->default_init():
>> + *		spi_nor_manufacturer_init_params()
>> + *
>> + * which can be overwritten by:
>> + * 3/ SFDP flash parameters initialization. JESD216 SFDP is a standard and
>> + *    should be more accurate that the above.
>> + *		spi_nor_sfdp_init_params()
>> + *
>> + *    Please not that there is a ->post_bfpt() fixup hook that can overwrite the
>> + *    flash parameters and settings imediately after parsing the Basic Flash
>> + *    Parameter Table.
>> + */
>> +static void spi_nor_init_params(struct spi_nor *nor)
>> +{
>> +	spi_nor_legacy_init_params(nor);
>>  
>>  	spi_nor_manufacturer_init_params(nor);
>>  
>> -	if ((info->flags & (SPI_NOR_DUAL_READ | SPI_NOR_QUAD_READ)) &&
>> -	    !(info->flags & SPI_NOR_SKIP_SFDP)) {
>> -		struct spi_nor_flash_parameter sfdp_params;
>> -
>> -		memcpy(&sfdp_params, params, sizeof(sfdp_params));
>> -
>> -		if (spi_nor_parse_sfdp(nor, &sfdp_params)) {
>> -			nor->addr_width = 0;
>> -			nor->flags &= ~SNOR_F_4B_OPCODES;
>> -		} else {
>> -			memcpy(params, &sfdp_params, sizeof(*params));
>> -		}
>> -	}
>> -
>> -	return 0;
>> +	if ((nor->info->flags & (SPI_NOR_DUAL_READ | SPI_NOR_QUAD_READ)) &&
>> +	    !(nor->info->flags & SPI_NOR_SKIP_SFDP))
>> +		spi_nor_sfdp_init_params(nor);
>>  }
>>  
>>  static int spi_nor_select_read(struct spi_nor *nor,
>> @@ -4693,10 +4738,8 @@ int spi_nor_scan(struct spi_nor *nor, const char *name,
>>  	    nor->info->flags & SPI_NOR_HAS_LOCK)
>>  		nor->params.disable_block_protection = spi_nor_clear_sr_bp;
>>  
>> -	/* Parse the Serial Flash Discoverable Parameters table. */
>> -	ret = spi_nor_init_params(nor);
>> -	if (ret)
>> -		return ret;
>> +	/* Init flash parameters based on flash_info struct and SFDP */
>> +	spi_nor_init_params(nor);
>>  
>>  	if (!mtd->name)
>>  		mtd->name = dev_name(dev);
> 
> 
>