Commit 66aaba3a authored May 03, 2020 by Boris Brezillon Committed by Miquel Raynal May 11, 2020

ubi: Relax the 'no MLC' rule and allow MLCs operating in SLC mode



The MTD layer provides an SLC mode (purely software emulation of SLC
behavior) addressing the paired-pages corruption issue, which was the
main reason for refusing attaching MLC NANDs to UBI.

Relax this rule and allow partitions that have the
MTD_EMULATE_SLC_ON_MLC flag set to be attached.

Signed-off-by: Boris Brezillon <bbrezillon@kernel.org>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Acked-by: Richard Weinberger <richard@nod.at>
Link: https://lore.kernel.org/linux-mtd/20200503155341.16712-9-miquel.raynal@bootlin.com

parent 568d841b

drivers/mtd/ubi/build.c

+4 −1

Original line number	Diff line number	Diff line
		@@ -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;

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