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>
Tue, 1 Oct 2019 06:26:02 +0000 (08:26 +0200)
commitc1a7fe48664745cac7929c630b24c56776c32f91
tree940464d87953e249e3d0725aebd5f7124eba2009
parent5fdefdcb92bbedc16460a934e353702b546729b9
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