From 89cf38dd536a7301d6b5f5ddd73f42074c01bfaa Mon Sep 17 00:00:00 2001 From: Dmitry Eremin-Solenikov Date: Thu, 23 Oct 2014 01:23:01 +0200 Subject: [PATCH] mtd: cfi_cmdset_0001.c: fix resume for LH28F640BF chips 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 Signed-off-by: Andrea Adami Cc: # 3.16+ Signed-off-by: Brian Norris --- 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); -- 2.20.1