mtd: cfi_cmdset_0002: Use chip_good() to retry in do_write_oneword()
authorTokunori Ikegami <ikegami.t@gmail.com>
Mon, 5 Aug 2019 19:03:18 +0000 (04:03 +0900)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Sat, 5 Oct 2019 10:47:33 +0000 (12:47 +0200)
commit4eb4e753976816875c7e4cb10e367607a6aa7612
tree84d7d0b5f6161b8cacbbf0b2a36a71ae1e2576f6
parentcaadb9e7e6d04807bc65b0a0e0d0a65a3c210b12
mtd: cfi_cmdset_0002: Use chip_good() to retry in do_write_oneword()

commit 37c673ade35c707d50583b5b25091ff8ebdeafd7 upstream.

As reported by the OpenWRT team, write requests sometimes fail on some
platforms.
Currently to check the state chip_ready() is used correctly as described by
the flash memory S29GL256P11TFI01 datasheet.
Also chip_good() is used to check if the write is succeeded and it was
implemented by the commit fb4a90bfcd6d8 ("[MTD] CFI-0002 - Improve error
checking").
But actually the write failure is caused on some platforms and also it can
be fixed by using chip_good() to check the state and retry instead.
Also it seems that it is caused after repeated about 1,000 times to retry
the write one word with the reset command.
By using chip_good() to check the state to be done it can be reduced the
retry with reset.
It is depended on the actual flash chip behavior so the root cause is
unknown.

Cc: Chris Packham <chris.packham@alliedtelesis.co.nz>
Cc: Joakim Tjernlund <Joakim.Tjernlund@infinera.com>
Cc: linux-mtd@lists.infradead.org
Cc: stable@vger.kernel.org
Reported-by: Fabio Bettoni <fbettoni@gmail.com>
Signed-off-by: Felix Fietkau <nbd@nbd.name>
Signed-off-by: Hauke Mehrtens <hauke@hauke-m.de>
Signed-off-by: Tokunori Ikegami <ikegami.t@gmail.com>
[vigneshr@ti.com: Fix a checkpatch warning]
Signed-off-by: Vignesh Raghavendra <vigneshr@ti.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
drivers/mtd/chips/cfi_cmdset_0002.c