mtd/nand:Fix wrong usage of is_blank() in fsl_ifc_run_command

[u-boot] / drivers / mtd / nand / mxc_nand.c

diff --git a/drivers/mtd/nand/mxc_nand.c b/drivers/mtd/nand/mxc_nand.c
index 78e07cc7f7b9cb339cd4715518daa27d915a86a0..35e89a0f4d69428878edcbe384263f02a7360b78 100644 (file)
--- a/drivers/mtd/nand/mxc_nand.c
+++ b/drivers/mtd/nand/mxc_nand.c
@@ -1371,7 +1371,18 @@ int board_nand_init(struct nand_chip *this)
 
        /* Blocks to be unlocked */
        writew(0x0, &host->regs->nfc_unlockstart_blkaddr);
-       writew(0x4000, &host->regs->nfc_unlockend_blkaddr);
+       /* Originally (Freescale LTIB 2.6.21) 0x4000 was written to the
+        * unlockend_blkaddr, but the magic 0x4000 does not always work
+        * when writing more than some 32 megabytes (on 2k page nands)
+        * However 0xFFFF doesn't seem to have this kind
+        * of limitation (tried it back and forth several times).
+        * The linux kernel driver sets this to 0xFFFF for the v2 controller
+        * only, but probably this was not tested there for v1.
+        * The very same limitation seems to apply to this kernel driver.
+        * This might be NAND chip specific and the i.MX31 datasheet is
+        * extremely vague about the semantics of this register.
+        */
+       writew(0xFFFF, &host->regs->nfc_unlockend_blkaddr);
 
        /* Unlock Block Command for given address range */
        writew(0x4, &host->regs->nfc_wrprot);