From: computersforpeace@gmail.com (Brian Norris)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCHv4 5/5] mtd: gpmi: prevent creating a new BBT when blockmark swapping is disabled
Date: Sun, 27 Jul 2014 22:29:06 -0700 [thread overview]
Message-ID: <20140728052906.GA3095@norris-Latitude-E6410> (raw)
In-Reply-To: <1402579245-13377-6-git-send-email-LW@KARO-electronics.de>
Hi Lothar,
On Thu, Jun 12, 2014 at 03:20:45PM +0200, Lothar Wa?mann wrote:
> Without blockmark swapping, there is no use in creating a BBT from
> scratch, so use a BBT descriptor with NAND_BBT_CREATE unset in this
> case.
I'm curious: what is your plan if there is no BBT available on your
device, or if it ever gets corrupted? IIUC, nand_bbt will just assume
you have no bad blocks, and it will never write a bad block table to
flash. This also means no subsequent discoverable bad blocks can be
recorded across power cycles, I believe.
Maybe you don't want to specify your own nand_bbt_descr's at all, but
you just need to set:
chip->bbt_options |= NAND_BBT_CREATE_EMPTY | NAND_BBT_NO_OOB;
(Note: there's a little bit of fuzziness about NAND_BBT_* flags, where
some are targeted for the nand_chip::bbt_options field, and others
belong in struct nand_bbt_descr::options.)
But if for some reason we need to keep this patch, a comment below:
> Signed-off-by: Lothar Wa?mann <LW@KARO-electronics.de>
> ---
> drivers/mtd/nand/gpmi-nand/gpmi-nand.c | 28 +++++++++++++++++++++++++++-
> 1 file changed, 27 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/mtd/nand/gpmi-nand/gpmi-nand.c b/drivers/mtd/nand/gpmi-nand/gpmi-nand.c
> index 37537b4..fc710d7 100644
> --- a/drivers/mtd/nand/gpmi-nand/gpmi-nand.c
> +++ b/drivers/mtd/nand/gpmi-nand/gpmi-nand.c
> @@ -43,6 +43,29 @@ static struct nand_bbt_descr gpmi_bbt_descr = {
> .pattern = scan_ff_pattern
> };
>
> +static uint8_t bbt_pattern[] = {'B', 'b', 't', '0' };
> +static uint8_t mirror_pattern[] = {'1', 't', 'b', 'B' };
> +
> +static struct nand_bbt_descr bbt_main_no_oob_descr = {
> + .options = NAND_BBT_LASTBLOCK | NAND_BBT_WRITE |
> + NAND_BBT_2BIT | NAND_BBT_VERSION | NAND_BBT_PERCHIP |
> + NAND_BBT_NO_OOB,
Please indent the above two lines a bit, preferably matching the
indentation of NAND_BBT_LASTBLOCK. It should be clear that this is a
continuation of the '.options' initialization.
> + .len = 4,
> + .veroffs = 4,
> + .maxblocks = NAND_BBT_SCAN_MAXBLOCKS,
> + .pattern = bbt_pattern,
> +};
> +
> +static struct nand_bbt_descr bbt_mirror_no_oob_descr = {
> + .options = NAND_BBT_LASTBLOCK | NAND_BBT_WRITE |
> + NAND_BBT_2BIT | NAND_BBT_VERSION | NAND_BBT_PERCHIP |
> + NAND_BBT_NO_OOB,
Same here.
> + .len = 4,
> + .veroffs = 4,
> + .maxblocks = NAND_BBT_SCAN_MAXBLOCKS,
> + .pattern = mirror_pattern,
> +};
> +
> /*
> * We may change the layout if we can get the ECC info from the datasheet,
> * else we will use all the (page + OOB).
> @@ -1728,8 +1751,11 @@ static int gpmi_nand_init(struct gpmi_nand_data *this)
> chip->bbt_options |= NAND_BBT_NO_OOB_BBM;
>
> if (of_property_read_bool(this->dev->of_node,
> - "fsl,no-blockmark-swap"))
> + "fsl,no-blockmark-swap")) {
> this->swap_block_mark = false;
> + chip->bbt_td = &bbt_main_no_oob_descr;
> + chip->bbt_md = &bbt_mirror_no_oob_descr;
My initial recommendation for this patch and the previous patch means
that you could just drop both patches and replace them with the
following:
/* Comment here to explain why... */
chip->bbt_options |= NAND_BBT_CREATE_EMPTY |
NAND_BBT_NO_OOB |
NAND_BBT_NO_OOB_BBM;
> + }
> }
> dev_dbg(this->dev, "Blockmark swapping %sabled\n",
> this->swap_block_mark ? "en" : "dis");
Brian
next prev parent reply other threads:[~2014-07-28 5:29 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-06-12 13:20 [PATCHv4 0/5] mtd: gpmi: make blockmark swapping optional Lothar Waßmann
2014-06-12 13:20 ` [PATCHv4 1/5] mtd: gpmi: remove useless (void *) type casts and spaces between type casts and variables Lothar Waßmann
2014-06-12 13:20 ` [PATCHv4 2/5] mtd: gpmi: remove line breaks from error messages and improve wording Lothar Waßmann
2014-06-12 13:20 ` [PATCHv4 3/5] mtd: gpmi: make blockmark swapping optional Lothar Waßmann
2014-06-12 13:20 ` [PATCHv4 4/5] of/mtd/nand: add generic binding and helper for NAND_BBT_NO_OOB_BBM Lothar Waßmann
2014-06-12 13:20 ` [PATCHv4 5/5] mtd: gpmi: prevent creating a new BBT when blockmark swapping is disabled Lothar Waßmann
2014-07-28 5:29 ` Brian Norris [this message]
2014-07-29 6:31 ` Lothar Waßmann
2014-07-24 2:06 ` [PATCHv4 4/5] of/mtd/nand: add generic binding and helper for NAND_BBT_NO_OOB_BBM Brian Norris
2014-07-24 6:49 ` Lothar Waßmann
2014-07-24 7:47 ` Brian Norris
2014-06-26 10:44 ` [PATCHv4 0/5] mtd: gpmi: make blockmark swapping optional Lothar Waßmann
2014-07-28 5:31 ` Brian Norris
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