Merge tag 'nand/for-5.8' of git://git.kernel.org/pub/scm/linux/kernel/git/mtd/linux into mtd/next

Raw NAND core changes:
* Stop using nand_release(), patched all drivers.
* Give more information about the ECC weakness when not matching the
  chip's requirement.
* MAINTAINERS updates.
* Support emulated SLC mode on MLC NANDs.
* Support "constrained" controllers, adapt the core and ONFI/JEDEC
  table parsing and Micron's code.
* Take check_only into account.
* Add an invalid ECC mode to discriminate with valid ones.
* Return an enum from of_get_nand_ecc_algo().
* Drop OOB_FIRST placement scheme.
* Introduce nand_extract_bits().
* Ensure a consistent bitflips numbering.
* BCH lib:
  - Allow easy bit swapping.
  - Rework a little bit the exported function names.
* Fix nand_gpio_waitrdy().
* Propage CS selection to sub operations.
* Add a NAND_NO_BBM_QUIRK flag.
* Give the possibility to verify a read operation is supported.
* Add a helper to check supported operations.
* Avoid indirect access to ->data_buf().
* Rename the use_bufpoi variables.
* Fix comments about the use of bufpoi.
* Rename a NAND chip option.
* Reorder the nand_chip->options flags.
* Translate obscure bitfields into readable macros.
* Timings:
  - Fix default values.
  - Add mode information to the timings structure.

Raw NAND controller driver changes:
* Fixed many error paths.
* Arasan
  - New driver
* Au1550nd:
  - Various cleanups
  - Migration to ->exec_op()
* brcmnand:
  - Misc cleanup.
  - Support v2.1-v2.2 controllers.
  - Remove unused including <linux/version.h>.
  - Correctly verify erased pages.
  - Fix Hamming OOB layout.
* Cadence
  - Make cadence_nand_attach_chip static.
* Cafe:
  - Set the NAND_NO_BBM_QUIRK flag
* cmx270:
  - Remove this controller driver.
* cs553x:
  - Misc cleanup
  - Migration to ->exec_op()
* Davinci:
  - Misc cleanup.
  - Migration to ->exec_op()
* Denali:
  - Add more delays before latching incoming data
* Diskonchip:
   - Misc cleanup
   - Migration to ->exec_op()
* Fsmc:
  - Change to non-atomic bit operations.
* GPMI:
  - Use nand_extract_bits()
  - Fix runtime PM imbalance.
* Ingenic:
  - Migration to exec_op()
  - Fix the RB gpio active-high property on qi, lb60
  - Make qi_lb60_ooblayout_ops static.
* Marvell:
   - Misc cleanup and small fixes
* Nandsim:
  - Fix the error paths, driver wide.
* Omap_elm:
  - Fix runtime PM imbalance.
* STM32_FMC2:
  - Misc cleanups (error cases, comments, timeout valus, cosmetic
    changes).

1 files changed, 4 insertions, 1 deletions

diff --git a/drivers/mtd/ubi/build.c b/drivers/mtd/ubi/build.c
index 12c02342149c..e85b04e9716b 100644
--- a/drivers/mtd/ubi/build.c
+++ b/drivers/mtd/ubi/build.c
@@ -867,8 +867,11 @@ int ubi_attach_mtd_dev(struct mtd_info *mtd, int ubi_num,
 	 * Both UBI and UBIFS have been designed for SLC NAND and NOR flashes.
 	 * MLC NAND is different and needs special care, otherwise UBI or UBIFS
 	 * will die soon and you will lose all your data.
+	 * Relax this rule if the partition we're attaching to operates in SLC
+	 * mode.
 	 */
-	if (mtd->type == MTD_MLCNANDFLASH) {
+	if (mtd->type == MTD_MLCNANDFLASH &&
+	    !(mtd->flags & MTD_SLC_ON_MLC_EMULATION)) {
 		pr_err("ubi: refuse attaching mtd%d - MLC NAND is not supported\n",
 			mtd->index);
 		return -EINVAL;