[patch 4/4] mtd/nand: fix multi-chip suspend problem

[akpm@linux-foundation.org]

From: Li Yang <leoli@freescale.com>

Symptom:
device_suspend(): mtd_cls_suspend+0x0/0x58 returns -11
PM: Device mtd14 failed to suspend: error -11
PM: Some devices failed to suspend

This patch enables other chips to be suspended if the active chip of
the controller has been suspended.

Signed-off-by: Jin Qing <b24347@freescale.com>
Signed-off-by: Li Yang <leoli@freescale.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 drivers/mtd/nand/nand_base.c |   14 ++++++++++----
 1 file changed, 10 insertions(+), 4 deletions(-)

diff -puN drivers/mtd/nand/nand_base.c~mtd-nand-fix-multi-chip-suspend-problem drivers/mtd/nand/nand_base.c
--- a/drivers/mtd/nand/nand_base.c~mtd-nand-fix-multi-chip-suspend-problem
+++ a/drivers/mtd/nand/nand_base.c
@@ -697,10 +697,16 @@ nand_get_device(struct nand_chip *chip, 
 		spin_unlock(lock);
 		return 0;
 	}
-	if (new_state == FL_PM_SUSPENDED) {
-		spin_unlock(lock);
-		return (chip->state == FL_PM_SUSPENDED) ? 0 : -EAGAIN;
-	}
+	if (new_state == FL_PM_SUSPENDED)
+		if (chip->controller->active->state == FL_PM_SUSPENDED) {
+			chip->state = FL_PM_SUSPENDED;
+			spin_unlock(lock);
+			return 0;
+		} else {
+			spin_unlock(lock);
+			return -EAGAIN;
+		}
+
 	set_current_state(TASK_UNINTERRUPTIBLE);
 	add_wait_queue(wq, &wait);
 	spin_unlock(lock);
_