[3.16.y-ckt extended stable] Patch "mtd: cfi_cmdset_0001.c: fix resume for LH28F640BF chips" has been added to staging queue

[Luis Henriques]

This is a note to let you know that I have just added a patch titled

    mtd: cfi_cmdset_0001.c: fix resume for LH28F640BF chips

to the linux-3.16.y-queue branch of the 3.16.y-ckt extended stable tree 
which can be found at:

 http://kernel.ubuntu.com/git?p=ubuntu/linux.git;a=shortlog;h=refs/heads/linux-3.16.y-queue

This patch is scheduled to be released in version 3.16.7-ckt1.

If you, or anyone else, feels it should not be added to this tree, please 
reply to this email.

For more information about the 3.16.y-ckt tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Luis

------

>From e8f0c0a7f94d8fc826ece9770e9bc7fcd21e4688 Mon Sep 17 00:00:00 2001
From: Dmitry Eremin-Solenikov <dbaryshkov at gmail.com>
Date: Thu, 23 Oct 2014 01:23:01 +0200
Subject: mtd: cfi_cmdset_0001.c: fix resume for LH28F640BF chips

commit 89cf38dd536a7301d6b5f5ddd73f42074c01bfaa upstream.

After '#echo mem > /sys/power/state' some devices can not be properly resumed
because apparently the MTD Partition Configuration Register has been reset
to default thus the rootfs cannot be mounted cleanly on resume.
An example of this can be found in the SA-1100 Developer's Manual at 9.5.3.3
where the second step of the Sleep Shutdown Sequence is described:
"An internal reset is applied to the SA-1100. All units are reset...".

As workaround we refresh the PCR value as done initially on chip setup.

This behavior and the fix are confirmed by our tests done on 2 different Zaurus
collie units with kernel 3.17.

Fixes: 812c5fa82bae: ("mtd: cfi_cmdset_0001.c: add support for Sharp LH28F640BF NOR")
Signed-off-by: Dmitry Eremin-Solenikov <dbaryshkov at gmail.com>
Signed-off-by: Andrea Adami <andrea.adami at gmail.com>
Signed-off-by: Brian Norris <computersforpeace at gmail.com>
Signed-off-by: Luis Henriques <luis.henriques at canonical.com>
---
 drivers/mtd/chips/cfi_cmdset_0001.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/mtd/chips/cfi_cmdset_0001.c b/drivers/mtd/chips/cfi_cmdset_0001.c
index a7543ba3e190..3096f3ded3ad 100644
--- a/drivers/mtd/chips/cfi_cmdset_0001.c
+++ b/drivers/mtd/chips/cfi_cmdset_0001.c
@@ -2590,6 +2590,8 @@ static void cfi_intelext_resume(struct mtd_info *mtd)

 		/* Go to known state. Chip may have been power cycled */
 		if (chip->state == FL_PM_SUSPENDED) {
+			/* Refresh LH28F640BF Partition Config. Register */
+			fixup_LH28F640BF(mtd);
 			map_write(map, CMD(0xFF), cfi->chips[i].start);
 			chip->oldstate = chip->state = FL_READY;
 			wake_up(&chip->wq);
--
2.1.0