Re: [PATCH v2 14/15] mtd: rawnand: Get rid of chip->numchips

From: Sascha Hauer <s.hauer@pengutronix.de>
To: Boris Brezillon <boris.brezillon@collabora.com>
Cc: Mason Yang <masonccyang@mxic.com.tw>, Vignesh R <vigneshr@ti.com>,
	Boris Brezillon <bbrezillon@kernel.org>,
	Julien Su <juliensu@mxic.com.tw>,
	Richard Weinberger <richard@nod.at>,
	Tudor Ambarus <Tudor.Ambarus@microchip.com>,
	Schrempf Frieder <frieder.schrempf@kontron.de>,
	Marek Vasut <marek.vasut@gmail.com>,
	Masahiro Yamada <yamada.masahiro@socionext.com>,
	linux-mtd@lists.infradead.org,
	Thomas Petazzoni <thomas.petazzoni@bootlin.com>,
	Miquel Raynal <miquel.raynal@bootlin.com>,
	Brian Norris <computersforpeace@gmail.com>,
	David Woodhouse <dwmw2@infradead.org>,
	linux-arm-kernel@lists.infradead.org
Subject: Re: [PATCH v2 14/15] mtd: rawnand: Get rid of chip->numchips
Date: Tue, 21 May 2019 09:56:46 +0200	[thread overview]
Message-ID: <20190521075646.2qhwtsgn54tev6jn@pengutronix.de> (raw)
In-Reply-To: <20190521093302.079f5470@collabora.com>

On Tue, May 21, 2019 at 09:33:02AM +0200, Boris Brezillon wrote:
> On Tue, 21 May 2019 08:59:48 +0200
> Sascha Hauer <s.hauer@pengutronix.de> wrote:
> 
> > Hi,
> > 
> > On Mon, Mar 04, 2019 at 09:15:21PM +0100, Miquel Raynal wrote:
> > > diff --git a/drivers/mtd/nand/raw/internals.h b/drivers/mtd/nand/raw/internals.h
> > > index fbf6ca015cd7..a204f9d7e123 100644
> > > --- a/drivers/mtd/nand/raw/internals.h
> > > +++ b/drivers/mtd/nand/raw/internals.h
> > > @@ -110,7 +110,7 @@ static inline int nand_exec_op(struct nand_chip *chip,
> > >  	if (!nand_has_exec_op(chip))
> > >  		return -ENOTSUPP;
> > >  
> > > -	if (WARN_ON(op->cs >= chip->numchips))
> > > +	if (WARN_ON(op->cs >= nanddev_ntargets(&chip->base)))
> > >  		return -EINVAL;  
> > 
> > This warning triggers when I apply my gpmi nand exec_op series.
> > 
> > The gpmi driver calls:
> > 
> > 	ret = nand_scan(chip, GPMI_IS_MX6(this) ? 2 : 1);
> > 
> > This ends up in nand_scan_ident() with maxchips = 2. Here nand_detect()
> > is called which sets memorg->ntargets = 1; Later in nand_scan_ident() we
> > have:
> > 
> > 	for (i = 1; i < maxchips; i++) {
> 
> This loop should be fixed to test against nanddev_ntargets() instead of
> maxchips.

This makes the maxchips argument to nand_scan() unused. A lot of drivers
are calling nand_scan() with maxchips > 1. How are these working then?

Or should there be a memorg->ntargets = maxchips before the loop?

Sascha

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