[PATCHv4 5/5] mtd: gpmi: prevent creating a new BBT when blockmark swapping is disabled
From: computersforpeace@gmail.com (Brian Norris)
Date: 2014-07-28 05:29:06
Also in:
linux-devicetree
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:
quoted hunk ↗ jump to hunk
Signed-off-by: Lothar Wa?mann <redacted> --- 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.
quoted hunk ↗ jump to hunk
+ .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