[PATCH v2 2/6] mtd: spi-nor: add erase die (chip) capability

[Tudor Ambarus]

On 11/3/23 14:58, Fabio Estevam wrote:
> On 03/11/2023 11:37, Tudor Ambarus wrote:
> 
>> I confirm I see the same behavior on n25q00 flash.
>> Erased 134217728 bytes from address 0x00000000 in flash
>>
>> real    3m49.082s
>> user    0m0.000s
>> sys    3m48.485s
>>
>> I'll continue to investigate this at a best effort rate, expect for some
>> delays, I'm handling SPI NOR mostly in my spare time. Happy to guide you
>> though. You may join #mtd irc channel for short questions, see where it
>> is in the MAINTAINERS file.
> 
> Thanks, Tudor.
> 
> Reading the datasheet at:
> https://www.micron.com/-/media/client/global/documents/products/data-sheet/nor-flash/serial-nor/mt25q/die-rev-b/mt25q_qlkt_u_01g_bbb_0.pdf
> 
> The last entry of Table 49 shows:
> 
> 512Mb bulk erase time: Typ: 153 s Max: 460 s
> 
> 512Mb corresponds to the size of one die.
> 
> mt25qu01g has two dies so the bulk erase time would be from 306 to 920 s
> (5 to 15 minutes!)
> 
> It seems that there is not much we can do about this long erase time.
> 
> Is my understanding correct?

Yes, I find your understanding correct.