mtd: nand: allow NAND_NO_SUBPAGE_WRITE to be set from driver

commit bf7a01bf7987b63b121d572b240c132ec44129c4 upstream.

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>
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/drivers/mtd/nand/nand_base.c b/drivers/mtd/nand/nand_base.c
index 47b19c0..eb9f5fb 100644
--- a/drivers/mtd/nand/nand_base.c
+++ b/drivers/mtd/nand/nand_base.c
@@ -2897,9 +2897,7 @@
 	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;
 
 	pr_info("ONFI flash detected\n");
 	return 1;
@@ -3064,9 +3062,8 @@
 			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