Re: [PATCH 2/2] mtd: spi-nor: Always use biggest erase size

[<Tudor.Ambarus@xxxxxxxxxxxxx>]

Hi, Alexander,

On 01/24/2019 01:21 PM, Sverdlin, Alexander (Nokia - DE/Ulm) wrote:
> Optimize erase time by always using biggest erase size for given erase
> request. Do it by removing "sector"-at-a-time erase code.
> spi_nor_erase_multi_sectors() seems to be mature enough to handle all
> the cases better.

Did you check if the upper mtd layers are affected by this change?

> 
> For the above to work backwards-compatible regarding 4-bytes commands
> spi_nor_set_4byte_opcodes() has to prepare them always, independent of
> spi_nor_has_uniform_erase() flag.
> 
> Remainder check in spi_nor_erase() becomes superfluous because
> spi_nor_erase_multi_sectors() performs it anyway.
> 
> The trigger for this change was n25q128a13: enabling SECT_4K increased
> erase time of 128k block from 1.763s to 11.335s.

When needed, one can disable the 4K sectors with the MTD_SPI_NOR_USE_4K_SECTORS
kconfig option. Does this help you?

Cheers,
ta
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