From 4355b70cf48363c50a9de450b01178c83aba8f6a Mon Sep 17 00:00:00 2001 From: Brian Norris Date: Tue, 27 Aug 2013 18:45:10 -0700 Subject: [PATCH] mtd: nand: hack ONFI for non-power-of-2 dimensions Some bright specification writers decided to write this in the ONFI spec (from ONFI 3.0, Section 3.1): "The number of blocks and number of pages per block is not required to be a power of two. In the case where one of these values is not a power of two, the corresponding address shall be rounded to an integral number of bits such that it addresses a range up to the subsequent power of two value. The host shall not access upper addresses in a range that is shown as not supported." This breaks every assumption MTD makes about NAND block/chip-size dimensions -- they *must* be a power of two! And of course, an enterprising manufacturer has made use of this lovely freedom. Exhibit A: Micron MT29F32G08CBADAWP "- Plane size: 2 planes x 1064 blocks per plane - Device size: 32Gb: 2128 blockss [sic]" This quickly hits a BUG() in nand_base.c, since the extra dimensions overflow so we think it's a second chip (on my single-chip setup): ONFI param page 0 valid ONFI flash detected NAND device: Manufacturer ID: 0x2c, Chip ID: 0x44 (Micron MT29F32G08CBADAWP), 4256MiB, page size: 8192, OOB size: 744 ------------[ cut here ]------------ kernel BUG at drivers/mtd/nand/nand_base.c:203! Internal error: Oops - BUG: 0 [#1] SMP ARM [... trim ...] [] (nand_select_chip+0x18/0x2c) from [] (nand_do_read_ops+0x90/0x424) [] (nand_do_read_ops+0x90/0x424) from [] (nand_read+0x54/0x78) [] (nand_read+0x54/0x78) from [] (mtd_read+0x84/0xbc) [] (mtd_read+0x84/0xbc) from [] (scan_read.clone.4+0x4c/0x64) [] (scan_read.clone.4+0x4c/0x64) from [] (search_bbt+0x148/0x290) [] (search_bbt+0x148/0x290) from [] (nand_scan_bbt+0xd4/0x5c0) [... trim ...] ---[ end trace 0c9363860d865ff2 ]--- So to fix this, just truncate these dimensions down to the greatest power-of-2 dimension that is less than or equal to the specified dimension. Signed-off-by: Brian Norris Cc: --- drivers/mtd/nand/nand_base.c | 15 +++++++++++++-- 1 file changed, 13 insertions(+), 2 deletions(-) diff --git a/drivers/mtd/nand/nand_base.c b/drivers/mtd/nand/nand_base.c index 848884473229..ec1db1e19c05 100644 --- a/drivers/mtd/nand/nand_base.c +++ b/drivers/mtd/nand/nand_base.c @@ -2987,10 +2987,21 @@ static int nand_flash_detect_onfi(struct mtd_info *mtd, struct nand_chip *chip, sanitize_string(p->model, sizeof(p->model)); if (!mtd->name) mtd->name = p->model; + mtd->writesize = le32_to_cpu(p->byte_per_page); - mtd->erasesize = le32_to_cpu(p->pages_per_block) * mtd->writesize; + + /* + * pages_per_block and blocks_per_lun may not be a power-of-2 size + * (don't ask me who thought of this...). MTD assumes that these + * dimensions will be power-of-2, so just truncate the remaining area. + */ + mtd->erasesize = 1 << (fls(le32_to_cpu(p->pages_per_block)) - 1); + mtd->erasesize *= mtd->writesize; + mtd->oobsize = le16_to_cpu(p->spare_bytes_per_page); - chip->chipsize = le32_to_cpu(p->blocks_per_lun); + + /* See erasesize comment */ + chip->chipsize = 1 << (fls(le32_to_cpu(p->blocks_per_lun)) - 1); chip->chipsize *= (uint64_t)mtd->erasesize * p->lun_count; chip->bits_per_cell = p->bits_per_cell; -- 2.20.1