mtd: nand: omap: Revert to using software ECC by default

For v3.12 and prior, 1-bit Hamming code ECC via software was the
default choice. Commit c66d039197e4 in v3.13 changed the behaviour
to use 1-bit Hamming code via Hardware using a different ECC layout
i.e. (ROM code layout) than what is used by software ECC.

This ECC layout change causes NAND filesystems created in v3.12
and prior to be unusable in v3.13 and later. So revert back to
using software ECC by default if an ECC scheme is not explicitely
specified.

This defect can be observed on the following boards during legacy boot

-omap3beagle
-omap3touchbook
-overo
-am3517crane
-devkit8000
-ldp
-3430sdp

Signed-off-by: Roger Quadros <rogerq@ti.com>
Tested-by: Grazvydas Ignotas <notasas@gmail.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>

1 files changed, 2 insertions, 1 deletions

diff --git a/arch/arm/mach-omap2/gpmc-nand.c b/arch/arm/mach-omap2/gpmc-nand.c
index 8897ad7035fd..cb7764314f17 100644
--- a/arch/arm/mach-omap2/gpmc-nand.c
+++ b/arch/arm/mach-omap2/gpmc-nand.c
@@ -49,7 +49,8 @@ static bool gpmc_hwecc_bch_capable(enum omap_ecc ecc_opt)
 		return 0;
 
 	/* legacy platforms support only HAM1 (1-bit Hamming) ECC scheme */
-	if (ecc_opt == OMAP_ECC_HAM1_CODE_HW)
+	if (ecc_opt == OMAP_ECC_HAM1_CODE_HW ||
+	    ecc_opt == OMAP_ECC_HAM1_CODE_SW)
 		return 1;
 	else
 		return 0;