mtd: return error code from mtd_unpoint

The 'mtd_unpoint()' API function should be able to return an error code because
it may fail if you specify incorrect offset. This patch changes this MTD API
function and amends all the drivers correspondingly.

Also return '-EOPNOTSUPP' from 'mtd_unpoint()' when the '->unpoint()' method is
undefined. We do not really need this currently, but this just makes
sense to be consistent with 'mtd_point()'.

Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>

1 files changed, 10 insertions, 6 deletions

diff --git a/drivers/mtd/chips/cfi_cmdset_0001.c b/drivers/mtd/chips/cfi_cmdset_0001.c
index 152accf4bf8..4d04551cffd 100644
--- a/drivers/mtd/chips/cfi_cmdset_0001.c
+++ b/drivers/mtd/chips/cfi_cmdset_0001.c
@@ -87,7 +87,7 @@ static int cfi_intelext_partition_fixup(struct mtd_info *, struct cfi_private **
 
 static int cfi_intelext_point (struct mtd_info *mtd, loff_t from, size_t len,
                      size_t *retlen, void **virt, resource_size_t *phys);
-static void cfi_intelext_unpoint(struct mtd_info *mtd, loff_t from, size_t len);
+static int cfi_intelext_unpoint(struct mtd_info *mtd, loff_t from, size_t len);
 
 static int chip_ready (struct map_info *map, struct flchip *chip, unsigned long adr, int mode);
 static int get_chip(struct map_info *map, struct flchip *chip, unsigned long adr, int mode);
@@ -1369,12 +1369,12 @@ static int cfi_intelext_point(struct mtd_info *mtd, loff_t from, size_t len,
         return 0;
 }
 
-static void cfi_intelext_unpoint(struct mtd_info *mtd, loff_t from, size_t len)
+static int cfi_intelext_unpoint(struct mtd_info *mtd, loff_t from, size_t len)
 {
         struct map_info *map = mtd->priv;
         struct cfi_private *cfi = map->fldrv_priv;
         unsigned long ofs;
-        int chipnum;
+        int chipnum, err = 0;
 
         /* Now unlock the chip(s) POINT state */
 
@@ -1382,7 +1382,7 @@ static void cfi_intelext_unpoint(struct mtd_info *mtd, loff_t from, size_t len)
         chipnum = (from >> cfi->chipshift);
         ofs = from - (chipnum <<  cfi->chipshift);
 
-        while (len) {
+        while (len && !err) {
                 unsigned long thislen;
                 struct flchip *chip;
 
@@ -1400,8 +1400,10 @@ static void cfi_intelext_unpoint(struct mtd_info *mtd, loff_t from, size_t len)
                         chip->ref_point_counter--;
                         if(chip->ref_point_counter == 0)
                                 chip->state = FL_READY;
-                } else
-                        printk(KERN_ERR "%s: Warning: unpoint called on non pointed region\n", map->name); /* Should this give an error? */
+                } else {
+                        printk(KERN_ERR "%s: Error: unpoint called on non pointed region\n", map->name);
+                        err = -EINVAL;
+                }
 
                 put_chip(map, chip, chip->start);
                 mutex_unlock(&chip->mutex);
@@ -1410,6 +1412,8 @@ static void cfi_intelext_unpoint(struct mtd_info *mtd, loff_t from, size_t len)
                 ofs = 0;
                 chipnum++;
         }
+
+        return err;
 }
 
 static inline int do_read_onechip(struct map_info *map, struct flchip *chip, loff_t adr, size_t len, u_char *buf)