Commit 3c9c6d65 authored by Mike Dunn's avatar Mike Dunn Committed by Artem Bityutskiy
Browse files

mtd: nand/docg4: fix and improve read of factory bbt 



This patch does two things related to reading the factory badblock table during
initialization: (1) fix error where a non-zero return code from
docg4_read_page() is assumed to be an error (it was later changed to be
max_bitflips; thanks to Brian Norris for bringing this to my attention a while
back), and (2) if there is an error reading the factory bbt, it tries reading
another (redundant) factory bbt table.

Signed-off-by: default avatarMike Dunn <mikedunn@newsguy.com>
Acked-by: default avatarRobert Jarzmik <robert.jarzmik@free.fr>
Signed-off-by: default avatarArtem Bityutskiy <artem.bityutskiy@linux.intel.com>
parent 440b1d73

drivers/mtd/nand/docg4.c

+19 −5
Original line number Diff line number Diff line
@@ -212,6 +212,7 @@ struct docg4_priv { 
#define DOCG4_T                4   /* BCH alg corrects up to 4 bit errors */



#define DOCG4_FACTORY_BBT_PAGE 16 /* page where read-only factory bbt lives */

#define DOCG4_REDUNDANT_BBT_PAGE 24 /* page where redundant factory bbt lives */



/*

 * Bytes 0, 1 are used as badblock marker.
@@ -1020,16 +1021,15 @@ static int __init read_factory_bbt(struct mtd_info *mtd) 
	struct docg4_priv *doc = nand->priv;

	uint32_t g4_addr = mtd_to_docg4_address(DOCG4_FACTORY_BBT_PAGE, 0);

	uint8_t *buf;

	int i, block, status;

	int i, block;

	__u32 eccfailed_stats = mtd->ecc_stats.failed;



	buf = kzalloc(DOCG4_PAGE_SIZE, GFP_KERNEL);

	if (buf == NULL)

		return -ENOMEM;



	read_page_prologue(mtd, g4_addr);

	status = docg4_read_page(mtd, nand, buf, 0, DOCG4_FACTORY_BBT_PAGE);

	if (status)

		goto exit;

	docg4_read_page(mtd, nand, buf, 0, DOCG4_FACTORY_BBT_PAGE);



	/*

	 * If no memory-based bbt was created, exit.  This will happen if module
@@ -1041,6 +1041,20 @@ static int __init read_factory_bbt(struct mtd_info *mtd) 
	if (nand->bbt == NULL)  /* no memory-based bbt */

		goto exit;



	if (mtd->ecc_stats.failed > eccfailed_stats) {

		/*

		 * Whoops, an ecc failure ocurred reading the factory bbt.

		 * It is stored redundantly, so we get another chance.

		 */

		eccfailed_stats = mtd->ecc_stats.failed;

		docg4_read_page(mtd, nand, buf, 0, DOCG4_REDUNDANT_BBT_PAGE);

		if (mtd->ecc_stats.failed > eccfailed_stats) {

			dev_warn(doc->dev,

				 "The factory bbt could not be read!\n");

			goto exit;

		}

	}



	/*

	 * Parse factory bbt and update memory-based bbt.  Factory bbt format is

	 * simple: one bit per block, block numbers increase left to right (msb
@@ -1060,7 +1074,7 @@ static int __init read_factory_bbt(struct mtd_info *mtd) 
	}

 exit:

	kfree(buf);

	return status;

	return 0;

}



static int docg4_block_markbad(struct mtd_info *mtd, loff_t ofs)

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