mtd: nand: allow NAND_NO_SUBPAGE_WRITE to be set from driver

This is based on Linux kernel -next:

commit 14f44abf1dafc20ba42ce8616a8fc8fbd1b3712b
Author: Brian Norris <computersforpeace@gmail.com>
Date:   Fri Jul 13 09:28:24 2012 -0700

    mtd: nand: allow NAND_NO_SUBPAGE_WRITE to be set from driver

    The NAND_CHIPOPTIONS_MSK has limited utility and is causing real bugs. It
    silently masks off at least one flag that might be set by the driver
    (NAND_NO_SUBPAGE_WRITE). This breaks the GPMI NAND driver and possibly
    others.

    Really, as long as driver writers exercise a small amount of care with
    NAND_* options, this mask is not necessary at all; it was only here to
    prevent certain options from accidentally being set by the driver. But the
    original thought turns out to be a bad idea occasionally. Thus, kill it.

    Note, this patch fixes some major gpmi-nand breakage.

Signed-off-by: Marek Vasut <marex@denx.de>
Cc: Brian Norris <computersforpeace@gmail.com>
Cc: Eric Nelson <eric.nelson@boundarydevices.com>
Cc: Fabio Estevam <festevam@gmail.com>
Cc: Otavio Salvador <otavio@ossystems.com.br>
Cc: Scott Wood <scottwood@freescale.com>
Signed-off-by: Scott Wood <scottwood@freescale.com>

drivers/mtd/nand/nand_base.c

@@ -2579,9 +2579,7 @@ static int nand_flash_detect_onfi(struct mtd_info *mtd, struct nand_chip *chip,
 	if (le16_to_cpu(p->features) & 1)
 		*busw = NAND_BUSWIDTH_16;
 
-	chip->options &= ~NAND_CHIPOPTIONS_MSK;
-	chip->options |= (NAND_NO_READRDY |
-			NAND_NO_AUTOINCR) & NAND_CHIPOPTIONS_MSK;
+	chip->options |= NAND_NO_READRDY | NAND_NO_AUTOINCR;
 
 	return 1;
 }
@@ -2753,8 +2751,7 @@ static const struct nand_flash_dev *nand_get_flash_type(struct mtd_info *mtd,
 		}
 	}
 	/* Get chip options, preserve non chip based options */
-	chip->options &= ~NAND_CHIPOPTIONS_MSK;
-	chip->options |= type->options & NAND_CHIPOPTIONS_MSK;
+	chip->options |= type->options;
 
 	/* Check if chip is a not a samsung device. Do not clear the
 	 * options for chips which are not having an extended id.

include/linux/mtd/nand.h

@@ -207,9 +207,6 @@ typedef enum {
 #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)
-
 /* Non chip related options */
 /*
  * Use a flash based bad block table. OOB identifier is saved in OOB area.