From mboxrd@z Thu Jan 1 00:00:00 1970 From: Archit Taneja Subject: [PATCH v3 1/5] mtd: nand: Create a BBT flag to access bad block markers in raw mode Date: Mon, 3 Aug 2015 10:38:14 +0530 Message-ID: <1438578498-32254-2-git-send-email-architt@codeaurora.org> References: <1421419702-17812-1-git-send-email-architt@codeaurora.org> <1438578498-32254-1-git-send-email-architt@codeaurora.org> Return-path: In-Reply-To: <1438578498-32254-1-git-send-email-architt@codeaurora.org> Sender: linux-kernel-owner@vger.kernel.org To: linux-mtd@lists.infradead.org, dehrenberg@google.com, cernekee@gmail.com, computersforpeace@gmail.com Cc: linux-arm-msm@vger.kernel.org, agross@codeaurora.org, sboyd@codeaurora.org, linux-kernel@vger.kernel.org, Archit Taneja List-Id: linux-arm-msm@vger.kernel.org Some controllers can access the factory bad block marker from OOB only when they read it in raw mode. When ECC is enabled, these controllers discard reading/writing bad block markers, preventing access to them altogether. The bbt driver assumes MTD_OPS_PLACE_OOB when scanning for bad blocks. This results in the nand driver's ecc->read_oob() op to be called, which works with ECC enabled. Create a new BBT option flag that tells nand_bbt to force the mode to MTD_OPS_RAW. This would result in the correct op being called for the underlying nand controller driver. Reviewed-by: Andy Gross Signed-off-by: Archit Taneja --- drivers/mtd/nand/nand_base.c | 6 +++++- drivers/mtd/nand/nand_bbt.c | 6 +++++- include/linux/mtd/bbm.h | 7 +++++++ 3 files changed, 17 insertions(+), 2 deletions(-) diff --git a/drivers/mtd/nand/nand_base.c b/drivers/mtd/nand/nand_base.c index ceb68ca..0a0c524 100644 --- a/drivers/mtd/nand/nand_base.c +++ b/drivers/mtd/nand/nand_base.c @@ -394,7 +394,11 @@ static int nand_default_block_markbad(struct mtd_info *mtd, loff_t ofs) } else { ops.len = ops.ooblen = 1; } - ops.mode = MTD_OPS_PLACE_OOB; + + if (unlikely(chip->bbt_options & NAND_BBT_ACCESS_BBM_RAW)) + ops.mode = MTD_OPS_RAW; + else + ops.mode = MTD_OPS_PLACE_OOB; /* Write to first/last page(s) if necessary */ if (chip->bbt_options & NAND_BBT_SCANLASTPAGE) diff --git a/drivers/mtd/nand/nand_bbt.c b/drivers/mtd/nand/nand_bbt.c index 63a1a36..f2d89c9 100644 --- a/drivers/mtd/nand/nand_bbt.c +++ b/drivers/mtd/nand/nand_bbt.c @@ -420,7 +420,11 @@ static int scan_block_fast(struct mtd_info *mtd, struct nand_bbt_descr *bd, ops.oobbuf = buf; ops.ooboffs = 0; ops.datbuf = NULL; - ops.mode = MTD_OPS_PLACE_OOB; + + if (unlikely(bd->options & NAND_BBT_ACCESS_BBM_RAW)) + ops.mode = MTD_OPS_RAW; + else + ops.mode = MTD_OPS_PLACE_OOB; for (j = 0; j < numpages; j++) { /* diff --git a/include/linux/mtd/bbm.h b/include/linux/mtd/bbm.h index 36bb6a5..f67f84a 100644 --- a/include/linux/mtd/bbm.h +++ b/include/linux/mtd/bbm.h @@ -116,6 +116,13 @@ struct nand_bbt_descr { #define NAND_BBT_NO_OOB_BBM 0x00080000 /* + * Force MTD_OPS_RAW mode when trying to access bad block markes from OOB. To + * be used by controllers which can access BBM only when ECC is disabled, i.e, + * when in RAW access mode + */ +#define NAND_BBT_ACCESS_BBM_RAW 0x00100000 + +/* * Flag set by nand_create_default_bbt_descr(), marking that the nand_bbt_descr * was allocated dynamicaly and must be freed in nand_release(). Has no meaning * in nand_chip.bbt_options. -- The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum, hosted by The Linux Foundation