tree ba4253248338d3e2a14350db4df34ae9fec7c44d
parent 8e40bf6f1cf1cf942c040d6b74fa473f991b22ab
author Nikita Kiryanov <nikita@compulab.co.il> 1387214341 +0200
committer Scott Wood <scottwood@freescale.com> 1387324013 -0600

mtd: nand: omap: fix sw->hw->sw ecc switch

When switching ecc mode, omap_select_ecc_scheme() assigns the appropriate values
into the current nand chip's ecc.layout struct. This is done under the
assumption that the struct exists only to store values, so it is OK to overwrite
it, but there is at least one situation where this assumption is incorrect:

When switching to 1 bit hamming code sw ecc, the job of assigning layout data
is outsourced to nand_scan_tail(), which simply assigns into ecc.layout a
pointer to an existing struct prefilled with the appropriate values. This struct
doubles as both data and layout definition, and therefore shouldn't be
overwritten, but on the next switch to hardware ecc, this is exactly what's
going to happen. The next time the user switches to software ecc, they're
going to get a messed up ecc layout.

Prevent this and possible similar bugs by explicitly using the
private-to-omap_gpmc.c omap_ecclayout struct when switching ecc mode.

Cc: Scott Wood <scottwood@freescale.com>
Cc: Pekon Gupta <pekon@ti.com>
Signed-off-by: Nikita Kiryanov <nikita@compulab.co.il>