mtd: edit comments on deprecation of ioctl ECCGETLAYOUT

[firefly-linux-kernel-4.4.55.git] / include / mtd / mtd-abi.h

diff --git a/include/mtd/mtd-abi.h b/include/mtd/mtd-abi.h
index 5bce08384345083c110f1c7da60174b512794f44..a57c4cb7d6b2efd3465c782375185d8fddcc402a 100644 (file)
--- a/include/mtd/mtd-abi.h
+++ b/include/mtd/mtd-abi.h
@@ -144,13 +144,18 @@ struct nand_oobfree {
 };
 
 #define MTD_MAX_OOBFREE_ENTRIES        8
+#define MTD_MAX_ECCPOS_ENTRIES 64
 /*
- * ECC layout control structure. Exported to userspace for
- * diagnosis and to allow creation of raw images
+ * OBSOLETE: ECC layout control structure. Exported to user-space via ioctl
+ * ECCGETLAYOUT for backwards compatbility and should not be mistaken as a
+ * complete set of ECC information. The ioctl truncates the larger internal
+ * structure to retain binary compatibility with the static declaration of the
+ * ioctl. Note that the "MTD_MAX_..._ENTRIES" macros represent the max size of
+ * the user struct, not the MAX size of the internal struct nand_ecclayout.
  */
 struct nand_ecclayout_user {
        __u32 eccbytes;
-       __u32 eccpos[64];
+       __u32 eccpos[MTD_MAX_ECCPOS_ENTRIES];
        __u32 oobavail;
        struct nand_oobfree oobfree[MTD_MAX_OOBFREE_ENTRIES];
 };