On Tue, 1 Nov 2016 13:16:25 -0500 Zach Brown <zach.br...@ni.com> wrote:
> For ONFI-compliant NAND devices, the ONFI parameters report the maximum number > of bad blocks per LUN that will be encountered over the lifetime of the > device, > so we can use that information to get a more accurate (and smaller) value for > the UBI bad PEB limit. > > The ONFI parameter "maxiumum number of bad blocks per LUN" is the max number > of > bad blocks that each individual LUN will ever ecounter. It is not the number > of > bad blocks to reserve for the nand device per LUN in the device. > > This means that in the worst case a UBI device spanning X LUNs will encounter > "maximum number of bad blocks per LUN" * X bad blocks. The implementation in > this patch assumes this worst case and allocates bad block accordingly. > > These patches are ordered in terms of their dependencies, but ideally, all 5 > would need to be applied for this to work as intended. This series looks good to me. Acked-by: Boris Brezillon <boris.brezil...@free-electron.com> Brian, Richard, any objections? > > v1: > * Changed commit message to address concerns from v1[1] about this patch set > making best case assumptions. > v2: > * Provided helper function for _max_bad_blocks > * Two new patches > * First new patch adds bb_per_lun and blocks_per_lun to nand_chip struct > * Second new patch sets the new fields during nand_flash_detect_onfi > * Max bad blocks calculation now uses the new nand_chip fields > v3: > * Changed bb_per_lun and blocks_per_lun to bb_per_die and blocks_per_die > * Corrected type of bb_per_die and blocks_per_die from little endian to host > unsigned int > > [1] > http://lkml.iu.edu/hypermail/linux/kernel/1505.1/04822.html > > > Jeff Westfahl (2): > mtd: introduce function max_bad_blocks > mtd: ubi: use 'max_bad_blocks' to compute bad_peb_limit if available > > Zach Brown (3): > mtd: nand: Add bb_per_die and blocks_per_die fields to nand_chip > mtd: nand: implement 'max_bad_blocks' mtd function > mtd: nand: set bb_per_die and blocks_per_die for ONFI compliant chips > > drivers/mtd/mtdpart.c | 13 +++++++++++++ > drivers/mtd/nand/nand_base.c | 39 +++++++++++++++++++++++++++++++++++++++ > drivers/mtd/ubi/build.c | 4 ++++ > include/linux/mtd/mtd.h | 11 +++++++++++ > include/linux/mtd/nand.h | 5 +++++ > 5 files changed, 72 insertions(+) > > -- > 2.7.4 >
