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Date:   Thu, 20 Dec 2018 15:07:26 +0100
From:   Boris Brezillon <bbrezillon@kernel.org>
To:     Schrempf Frieder <frieder.schrempf@kontron.de>
Cc:     "richard@nod.at" <richard@nod.at>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
        Marek Vasut <marek.vasut@gmail.com>,
        "linux-mtd@lists.infradead.org" <linux-mtd@lists.infradead.org>,
        "miquel.raynal@bootlin.com" <miquel.raynal@bootlin.com>,
        Brian Norris <computersforpeace@gmail.com>,
        David Woodhouse <dwmw2@infradead.org>
Subject: Re: [PATCH 1/3] mtd: rawnand: Support bad block markers in first,
 second or last page
Message-ID: <20181220150715.5b19f480@bbrezillon>
In-Reply-To: <20181220145954.55ae36e9@bbrezillon>
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        <20181220145954.55ae36e9@bbrezillon>
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On Thu, 20 Dec 2018 14:59:54 +0100
Boris Brezillon <boris.brezillon@bootlin.com> wrote:

> >  
> >  /**
> > + * nand_bbm_page_offset - Get the page offsets for bad block markers
> > + * @chip: NAND chip object
> > + * @index: Index for the page offset  
> 
> Hm, the meaning of index is far from obvious. How about passing the
> current page instead (and return 1 if there are more pages to scan 0
> otherwise)?
> 
> Something like:
> 
> static int nand_bbm_get_next_page(struct nand_chip *chip, int page)
> {
> 	struct mtd_info *mtd = nand_to_mtd(chip);
> 	int last_page = ((mtd->erasesize - mtd->writesize) >>
> 			 chip->page_shift) & chip->pagemask;
> 
> 	if (page < 0 && chip->bbt_options & NAND_BBT_SCANFIRSTPAGE)
> 		return 0;
> 	else if (page < 1 && chip->bbt_options & NAND_BBT_SCAN2NDPAGE)
> 		return 1;
> 	else if (page < last_page &&
> 		 chip->bbt_options & NAND_BBT_SCANLASTPAGE)
> 		return last_page;
> 
> 	return -1;
> }
> 
> And yes, that means defining NAND_BBT_SCANFIRSTPAGE and setting it when
> appropriate.
> 

Oh, and you'll have to define NAND_BBT_SCANFIRST2PAGES like this

#define NAND_BBT_SCANFIRST2PAGES NAND_BBT_SCAN1STPAGE |	\
				 NAND_BBT_SCAN2NDPAGE

and then patch all users of NAND_BBT_SCAN2NDPAGE to use
NAND_BBT_SCANFIRST2PAGES instead.