[PATCH] mtd: cfi_cmdset_0002: Change erase functions to retry for error

[IKEGAMI Tokunori]

Hi Boris-san,

Thanks for your reviewing.

> > This is needed to prevent the flash erase error caused only once.
> > It was caused by the error case of chip_good() in the do_erase_oneblock().
> > Also it was confirmed on the MACRONIX flash device MX29GL512FHT2I-11G.
> > But the error issue behavior is not able to reproduce at this moment.
> 
> Hm, that's a problem. How can you be sure the retry approach fixes the
> issue if you can't reproduce the it?

  I can reproduce the flash write error by the same reproduction method.
  And the error can be resolved by the same approach fixes as below.
    <http://lists.infradead.org/pipermail/linux-mtd/2018-May/080794.html>
  So it seems that the erase error also can be resolved by the changes.

> > The flash controller is parallel Flash interface integrated on BCM53003.
> >
> > Also the change is possible to resolve other erase error.
> > For example the Erase suspend issue was caused on Cypress AMD NOR flash.
> >   S29GL01GS / S29GL512S / S29GL256S / S29GL128S
> 
> Is the Erase suspend issue related to this problem?

  I am not sure about the issue behavior detail since the issue is not caused on my environment.
  The issue was mentioned by Jocke-san on the following mail.
    <http://lists.infradead.org/pipermail/linux-mtd/2018-April/080518.html>
  Also I am asking to him to try the original patch on this thread.

Regards,
Ikegami