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: Brian Norris <computersforpeace@gmail.com>
Tested-by: Huang Shijie <shijie8@gmail.com>
Cc: stable@vger.kernel.org
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>

1 files changed, 2 insertions, 5 deletions

diff --git a/drivers/mtd/nand/nand_base.c b/drivers/mtd/nand/nand_base.c
index ead301a455ee..996cc4836885 100644
--- a/drivers/mtd/nand/nand_base.c
+++ b/drivers/mtd/nand/nand_base.c
@@ -2909,8 +2909,6 @@ 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;
-
         pr_info("ONFI flash detected\n");
         return 1;
 }
@@ -3074,9 +3072,8 @@ static struct nand_flash_dev *nand_get_flash_type(struct mtd_info *mtd,
                         mtd->erasesize <<= ((id_data[3] & 0x03) << 1);
                 }
         }
-        /* Get chip options, preserve non chip based options */
-        chip->options &= ~NAND_CHIPOPTIONS_MSK;
-        chip->options |= type->options & NAND_CHIPOPTIONS_MSK;
+        /* Get chip options */
+        chip->options |= type->options;
 
         /*
          * Check if chip is not a Samsung device. Do not clear the