Re: [RESEND PATCH v5 0/5] mtd: use ONFI bad blocks per LUN to calculate UBI bad PEB limit
From: Boris Brezillon
Date: Tue Nov 22 2016 - 04:37:14 EST
Please do not resend a patch series so quickly (a simple ping is
BTW, I already asked Richard and Brian to have a look, let's wait a bit.
On Mon, 21 Nov 2016 13:51:34 -0600
Zach Brown <zach.brown@xxxxxx> 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.
> * Changed commit message to address concerns from v1 about this patch set
> making best case assumptions.
> * 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
> * 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
> * Changed bb_per_die to max_bb_per_die
> * Fixed spacing style issue
> 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 max_bb_per_die and blocks_per_die fields to nand_chip
> mtd: nand: implement 'max_bad_blocks' mtd function
> mtd: nand: set max_bb_per_die and blocks_per_die for ONFI compliant
> drivers/mtd/mtdpart.c | 12 ++++++++++++
> drivers/mtd/nand/nand_base.c | 38 ++++++++++++++++++++++++++++++++++++++
> drivers/mtd/ubi/build.c | 4 ++++
> include/linux/mtd/mtd.h | 11 +++++++++++
> include/linux/mtd/nand.h | 5 +++++
> 5 files changed, 70 insertions(+)