From mboxrd@z Thu Jan 1 00:00:00 1970 From: ben-linux@fluff.org (Ben Dooks) Date: Tue, 8 Dec 2009 12:16:08 +0000 Subject: [PATCH] [NAND] S3C2410: Fix NFC clock enable/disable imbalance In-Reply-To: <200912081307.17955.jbe@pengutronix.de> References: <200912081056.40210.jbe@pengutronix.de> <4B1E3815.9020901@ru.mvista.com> <200912081307.17955.jbe@pengutronix.de> Message-ID: <20091208121607.GA20364@trinity.fluff.org> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On Tue, Dec 08, 2009 at 01:07:17PM +0100, Juergen Beisert wrote: > On Dienstag, 8. Dezember 2009, Sergei Shtylyov wrote: > > Hello. > > > > Juergen Beisert wrote: > > > When unmounting an mtd filesystem the s3c2410_nand_select_chip() function > > > gets called again with "chip == -1". In this case the current code > > > disables the NFC clock at least a second time, so it does not work > > > anymore. Clock disabling should only happen if it was really enabled. > > > > > > Signed-off-by: Juergen Beisert > > > > > > --- > > > drivers/mtd/nand/s3c2410.c | 8 ++++++-- > > > 1 file changed, 6 insertions(+), 2 deletions(-) > > > > > > Index: linux-2.6.32/drivers/mtd/nand/s3c2410.c > > > =================================================================== > > > --- linux-2.6.32.orig/drivers/mtd/nand/s3c2410.c > > > +++ linux-2.6.32/drivers/mtd/nand/s3c2410.c > > > @@ -329,12 +329,16 @@ static void s3c2410_nand_select_chip(str > > > struct s3c2410_nand_mtd *nmtd; > > > struct nand_chip *this = mtd->priv; > > > unsigned long cur; > > > + int clock_enabled; > > > > Could be *bool*... > > I'm not sure. When this function is called more than once to disable a NAND > device chip select, who knows if it might be called more than once to enable > it? Just an idea. it might be worth tracking the clock state, not only in these case but to ensure that things like suspend/resume cycles don't cause problems too. -- Ben Q: What's a light-year? A: One-third less calories than a regular year.