[source] ar71xx: Fix UBIFS work on Mikrotik RB95x devices

[LEDE Commits]

nbd pushed a commit to source.git, branch lede-17.01:
https://git.lede-project.org/d71ffb9639564b91b92355fe35a72e0ed7cd2298

commit d71ffb9639564b91b92355fe35a72e0ed7cd2298
Author: Sergey Sergeev <adron at yapic.net>
AuthorDate: Wed May 31 11:00:01 2017 +0300

    ar71xx: Fix UBIFS work on Mikrotik RB95x devices
    
    If nand chip has no NAND_NO_SUBPAGE_WRITE flag on its options
    ubifs can't use it mtd devices and the kernel crashes with error:
    __nand_correct_data: uncorrectable ECC error
    
    Signed-off-by: Sergey Sergeev <adron at yapic.net>
---
 target/linux/ar71xx/files/arch/mips/ath79/mach-rb95x.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/target/linux/ar71xx/files/arch/mips/ath79/mach-rb95x.c b/target/linux/ar71xx/files/arch/mips/ath79/mach-rb95x.c
index 05e15e7..e940d6c 100644
--- a/target/linux/ar71xx/files/arch/mips/ath79/mach-rb95x.c
+++ b/target/linux/ar71xx/files/arch/mips/ath79/mach-rb95x.c
@@ -165,6 +165,8 @@ static int rb95x_nand_scan_fixup(struct mtd_info *mtd)
 		chip->ecc.layout = &rb95x_nand_ecclayout;
 	}
 
+	chip->options = NAND_NO_SUBPAGE_WRITE;
+
 	return 0;
 }