From patchwork Mon Nov 23 20:24:03 2009
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Subject: [4/4] mtd/nand: fix multi-chip suspend problem
From: Andrew Morton <akpm@linux-foundation.org>
X-Patchwork-Id: 39095
Message-Id: <20091123122403.d9073471.akpm@linux-foundation.org>
To: dedekind1@gmail.com
Cc: b24347@freescale.com, leoli@freescale.com, dwmw2@infradead.org,
 linux-mtd@lists.infradead.org
Date: Mon, 23 Nov 2009 12:24:03 -0800

On Mon, 23 Nov 2009 17:19:04 +0200
Artem Bityutskiy <dedekind1@gmail.com> wrote:

> On Tue, 2009-11-17 at 14:45 -0800, akpm@linux-foundation.org wrote:
> > 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);
> 
> This patch casing the following gcc warning:
> 
> drivers/mtd/nand/nand_base.c: In function ___nand_get_device___:
> drivers/mtd/nand/nand_base.c:700: warning: suggest explicit braces to
> avoid ambiguous ___else___
> 

Stupid gcc.


--- a/drivers/mtd/nand/nand_base.c~mtd-nand-fix-multi-chip-suspend-problem-fix
+++ a/drivers/mtd/nand/nand_base.c
@@ -697,7 +697,7 @@ nand_get_device(struct nand_chip *chip, 
 		spin_unlock(lock);
 		return 0;
 	}
-	if (new_state == FL_PM_SUSPENDED)
+	if (new_state == FL_PM_SUSPENDED) {
 		if (chip->controller->active->state == FL_PM_SUSPENDED) {
 			chip->state = FL_PM_SUSPENDED;
 			spin_unlock(lock);
@@ -706,7 +706,7 @@ nand_get_device(struct nand_chip *chip, 
 			spin_unlock(lock);
 			return -EAGAIN;
 		}
-
+	}
 	set_current_state(TASK_UNINTERRUPTIBLE);
 	add_wait_queue(wq, &wait);
 	spin_unlock(lock);