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Commit 96d8b647 authored by Alexey Korolev's avatar Alexey Korolev Committed by David Woodhouse
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[MTD] [NAND] fix subpage read for small page NAND 



Current implementation of subpage read feature for NAND has issues with
small page devices. Small page NAND do not support RNDOUT command.
So subpage feature is not applicable for them.

This patch disables support of subpage for small page NAND.
The code is verified on nandsim(SP NAND simulation) and on LP NAND
devices.

Thanks a lot to Artem for finding this issue.

Signed-off-by: default avatarAlexey Korolev <akorolev@infradead.org>
Signed-off-by: default avatarArtem Bityutskiy <Artem.Bityutskiy@nokia.com>
Signed-off-by: default avatarDavid Woodhouse <David.Woodhouse@intel.com>
parent 6e86841d

include/linux/mtd/nand.h

+3 −1
Original line number Diff line number Diff line
@@ -177,7 +177,9 @@ typedef enum { 
#define NAND_MUST_PAD(chip) (!(chip->options & NAND_NO_PADDING))

#define NAND_HAS_CACHEPROG(chip) ((chip->options & NAND_CACHEPRG))

#define NAND_HAS_COPYBACK(chip) ((chip->options & NAND_COPYBACK))

#define NAND_SUBPAGE_READ(chip) ((chip->ecc.mode == NAND_ECC_SOFT))

/* Large page NAND with SOFT_ECC should support subpage reads */

#define NAND_SUBPAGE_READ(chip) ((chip->ecc.mode == NAND_ECC_SOFT) \

					&& (chip->page_shift > 9))



/* Mask to zero out the chip options, which come from the id table */

#define NAND_CHIPOPTIONS_MSK	(0x0000ffff & ~NAND_NO_AUTOINCR)