1 files changed, 13 insertions, 8 deletions

diff --git a/drivers/mtd/devices/docg3.c b/drivers/mtd/devices/docg3.c
index 3eafef383a39..2c1d0fca6757 100644
--- a/drivers/mtd/devices/docg3.c
+++ b/drivers/mtd/devices/docg3.c
@@ -734,7 +734,7 @@ err:
  * doc_read_page_getbytes - Reads bytes from a prepared page
  * @docg3: the device
  * @len: the number of bytes to be read (must be a multiple of 4)
- * @buf: the buffer to be filled in
+ * @buf: the buffer to be filled in (or NULL is forget bytes)
  * @first: 1 if first time read, DOC_READADDRESS should be set
  *
  */
@@ -849,7 +849,7 @@ static int doc_read_oob(struct mtd_info *mtd, loff_t from,
                         struct mtd_oob_ops *ops)
 {
         struct docg3 *docg3 = mtd->priv;
-        int block0, block1, page, ret, ofs = 0;
+        int block0, block1, page, ret, skip, ofs = 0;
         u8 *oobbuf = ops->oobbuf;
         u8 *buf = ops->datbuf;
         size_t len, ooblen, nbdata, nboob;
@@ -869,8 +869,7 @@ static int doc_read_oob(struct mtd_info *mtd, loff_t from,
 
         doc_dbg("doc_read_oob(from=%lld, mode=%d, data=(%p:%zu), oob=(%p:%zu))\n",
                 from, ops->mode, buf, len, oobbuf, ooblen);
-        if ((len % DOC_LAYOUT_PAGE_SIZE) || (ooblen % DOC_LAYOUT_OOB_SIZE) ||
-            (from % DOC_LAYOUT_PAGE_SIZE))
+        if (ooblen % DOC_LAYOUT_OOB_SIZE)
                 return -EINVAL;
 
         ret = -EINVAL;
@@ -882,10 +881,11 @@ static int doc_read_oob(struct mtd_info *mtd, loff_t from,
         ops->oobretlen = 0;
         ops->retlen = 0;
         ret = 0;
+        skip = from % DOC_LAYOUT_PAGE_SIZE;
         while (!ret && (len > 0 || ooblen > 0)) {
-                calc_block_sector(from, &block0, &block1, &page, &ofs,
+                calc_block_sector(from - skip, &block0, &block1, &page, &ofs,
                         docg3->reliable);
-                nbdata = min_t(size_t, len, (size_t)DOC_LAYOUT_PAGE_SIZE);
+                nbdata = min_t(size_t, len, DOC_LAYOUT_PAGE_SIZE - skip);
                 nboob = min_t(size_t, ooblen, (size_t)DOC_LAYOUT_OOB_SIZE);
                 ret = doc_read_page_prepare(docg3, block0, block1, page, ofs);
                 if (ret < 0)
@@ -893,10 +893,14 @@ static int doc_read_oob(struct mtd_info *mtd, loff_t from,
                 ret = doc_read_page_ecc_init(docg3, DOC_ECC_BCH_TOTAL_BYTES);
                 if (ret < 0)
                         goto err_in_read;
-                ret = doc_read_page_getbytes(docg3, nbdata, buf, 1);
+                ret = doc_read_page_getbytes(docg3, skip, NULL, 1);
+                if (ret < skip)
+                        goto err_in_read;
+                ret = doc_read_page_getbytes(docg3, nbdata, buf, 0);
                 if (ret < nbdata)
                         goto err_in_read;
-                doc_read_page_getbytes(docg3, DOC_LAYOUT_PAGE_SIZE - nbdata,
+                doc_read_page_getbytes(docg3,
+                                       DOC_LAYOUT_PAGE_SIZE - nbdata - skip,
                                        NULL, 0);
                 ret = doc_read_page_getbytes(docg3, nboob, oobbuf, 0);
                 if (ret < nboob)
@@ -950,6 +954,7 @@ static int doc_read_oob(struct mtd_info *mtd, loff_t from,
                 len -= nbdata;
                 ooblen -= nboob;
                 from += DOC_LAYOUT_PAGE_SIZE;
+                skip = 0;
         }
 
         return ret;