RE: [PATCH] Add optional chip erase functionality to AT25 EEPROM driver.

David Laight
2019-08-12T15:51:41Z

From: Joe Burmeister
> Sent: 09 August 2019 13:54
>
> Many, though not all, AT25s have an instruction for chip erase.
> If there is one in the datasheet, it can be added to device tree.
> Erase can then be done in userspace via the sysfs API with a new
> "erase" device attribute. This matches the eeprom_93xx46 driver's
> "erase".

Is it actually worth doing though?

I'm guessing that device erase can easily take over a minute.

When I looked at 'device erase' on an EEPROM it took just as long
as erasing the sectors one at a time - but without the warm cosy
feeling that progress was being made.

Not only that you can't really interrupt the erase, so either
the application has to sleep uninterruptibly for the duration
or you have to have some kind of 'device busy' response while
it is done asynchronously.

David

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