Re: Re: [PATCH] cfi: fix deadloop in cfi_cmdset_0002.c do_write_buffer

[Joakim Tjernlund]

On Thu, 2019-02-07 at 23:50 +0000, Sobon, Przemyslaw wrote:
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> Hi Ikegami,
> 
> I have seen a case myself where a value was written, chip changed
> state to "ready" but when I was reading the value was incorrect.
> This can happen as result of intermittent issue with flash. It is
> hard to fall into scenario when testing on limited number of devices
> but with large enough population you can see that. Another situation
> is when a flash chip reaches its maximum number of writes. So for
> example a chip is designed for 100k writes to a page. Once you
> reach that number of writes you can have invalid data written to
> flash but chip itself reports everything was good and switches to
> "ready" state.

This makes perfekt sense but the AMD flash control I/F does not. You will
find that trying to do advanced things with "toggle" bits is very hard.
Especially when you also need to scale it to interleaved flashes.

I think the odd delay when flash fails is quite OK. If you want to
fix this you need to move the other control I/F(which mimics what Intel has)

 Jocke