mtdblock: Add comment about UBI block devices

There is a surprisingly large number of tutorials
that suggest using mtdblock to mount SquashFS filesystems
on flash devices, including NAND devices.

Given this approach is suboptimal than using UBI, and given
the UBI block device layer was introduced many years ago
specifically with this use case in mind, add a small
comment inviting users and developers to consider UBI block.

Signed-off-by: Ezequiel Garcia <ezequiel@collabora.com>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://lore.kernel.org/linux-mtd/20210801234509.18774-7-ezequiel@collabora.com

diff --git a/drivers/mtd/Kconfig b/drivers/mtd/Kconfig
index 3a1f87def25b57c21d43a58defe1d27a829af39c..796a2eccbef0b873585adc28208a505cfd3933b5 100644 (file)
--- a/drivers/mtd/Kconfig
+++ b/drivers/mtd/Kconfig
@@ -69,6 +69,9 @@ config MTD_BLOCK_RO
          You do not need this option for use with the DiskOnChip devices. For
          those, enable NFTL support (CONFIG_NFTL) instead.
 
+comment "Note that in some cases UBI block is preferred. See MTD_UBI_BLOCK."
+       depends on MTD_BLOCK || MTD_BLOCK_RO
+
 config FTL
        tristate "FTL (Flash Translation Layer) support"
        depends on BLOCK