mtd: docg3: fix reading oob+data without correction
authorRobert Jarzmik <robert.jarzmik@free.fr>
Sat, 19 Nov 2011 15:02:47 +0000 (16:02 +0100)
committerDavid Woodhouse <David.Woodhouse@intel.com>
Mon, 9 Jan 2012 18:07:17 +0000 (18:07 +0000)
Fix the docg3 reads to be able to cope with all possible
data buffer / oob buffer / file mode combinations from
docg3_read_oob().
This especially ensures that raw reads do not use ECC
corrections, and AUTOOOB and PLACEOOB do use ECC
correction.

The approach is to empty docg3_read() and make it a wrapper
to docg3_read_oob(). As docg3_read_oob() handles all the
funny cases (no data buffer but oob buffer, data buffer but
no oob buffer, ...), docg3_read() is just a special use of
docg3_read_oob().

Signed-off-by: Robert Jarzmik <robert.jarzmik@free.fr>
Reviewed-by: Ivan Djelic <ivan.djelic@parrot.com>
Reviewed-by: Mike Dunn <mikedunn@newsguy.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
drivers/mtd/devices/docg3.c

index 5834e6e65d1c2b10988b339d61a38945f2da32ef..1c2f54d23c7e547ca2f175b66e1a8f04d257b3e3 100644 (file)
@@ -196,8 +196,8 @@ static int doc_reset_seq(struct docg3 *docg3)
 /**
  * doc_read_data_area - Read data from data area
  * @docg3: the device
- * @buf: the buffer to fill in
- * @len: the lenght to read
+ * @buf: the buffer to fill in (might be NULL is dummy reads)
+ * @len: the length to read
  * @first: first time read, DOC_READADDRESS should be set
  *
  * Reads bytes from flash data. Handles the single byte / even bytes reads.
@@ -218,8 +218,10 @@ static void doc_read_data_area(struct docg3 *docg3, void *buf, int len,
        dst16 = buf;
        for (i = 0; i < len4; i += 2) {
                data16 = doc_readw(docg3, DOC_IOSPACE_DATA);
-               *dst16 = data16;
-               dst16++;
+               if (dst16) {
+                       *dst16 = data16;
+                       dst16++;
+               }
        }
 
        if (cdr) {
@@ -229,8 +231,10 @@ static void doc_read_data_area(struct docg3 *docg3, void *buf, int len,
                dst8 = (u8 *)dst16;
                for (i = 0; i < cdr; i++) {
                        data8 = doc_readb(docg3, DOC_IOSPACE_DATA);
-                       *dst8 = data8;
-                       dst8++;
+                       if (dst8) {
+                               *dst8 = data8;
+                               dst8++;
+                       }
                }
        }
 }
@@ -542,96 +546,109 @@ static void calc_block_sector(loff_t from, int *block0, int *block1, int *page,
 }
 
 /**
- * doc_read - Read bytes from flash
+ * doc_read_oob - Read out of band bytes from flash
  * @mtd: the device
  * @from: the offset from first block and first page, in bytes, aligned on page
  *        size
- * @len: the number of bytes to read (must be a multiple of 4)
- * @retlen: the number of bytes actually read
- * @buf: the filled in buffer
+ * @ops: the mtd oob structure
  *
- * Reads flash memory pages. This function does not read the OOB chunk, but only
- * the page data.
+ * Reads flash memory OOB area of pages.
  *
  * Returns 0 if read successfull, of -EIO, -EINVAL if an error occured
  */
-static int doc_read(struct mtd_info *mtd, loff_t from, size_t len,
-            size_t *retlen, u_char *buf)
+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, readlen, ret, ofs = 0;
-       int syn[DOC_ECC_BCH_SIZE], eccconf1;
-       u8 oob[DOC_LAYOUT_OOB_SIZE];
+       int block0, block1, page, ret, ofs = 0;
+       u8 *oobbuf = ops->oobbuf;
+       u8 *buf = ops->datbuf;
+       size_t len, ooblen, nbdata, nboob;
+       u8 calc_ecc[DOC_ECC_BCH_SIZE], eccconf1;
+
+       if (buf)
+               len = ops->len;
+       else
+               len = 0;
+       if (oobbuf)
+               ooblen = ops->ooblen;
+       else
+               ooblen = 0;
+
+       if (oobbuf && ops->mode == MTD_OPS_PLACE_OOB)
+               oobbuf += ops->ooboffs;
+
+       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))
+               return -EINVAL;
 
        ret = -EINVAL;
-       doc_dbg("doc_read(from=%lld, len=%zu, buf=%p)\n", from, len, buf);
-       if (from % DOC_LAYOUT_PAGE_SIZE)
-               goto err;
-       if (len % 4)
-               goto err;
-       calc_block_sector(from, &block0, &block1, &page, &ofs);
+       calc_block_sector(from + len, &block0, &block1, &page, &ofs);
        if (block1 > docg3->max_block)
                goto err;
 
-       *retlen = 0;
+       ops->oobretlen = 0;
+       ops->retlen = 0;
        ret = 0;
-       readlen = min_t(size_t, len, (size_t)DOC_LAYOUT_PAGE_SIZE);
-       while (!ret && len > 0) {
-               readlen = min_t(size_t, len, (size_t)DOC_LAYOUT_PAGE_SIZE);
+       while (!ret && (len > 0 || ooblen > 0)) {
+               calc_block_sector(from, &block0, &block1, &page, &ofs);
+               nbdata = min_t(size_t, len, (size_t)DOC_LAYOUT_PAGE_SIZE);
+               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)
                        goto err;
                ret = doc_read_page_ecc_init(docg3, DOC_ECC_BCH_COVERED_BYTES);
                if (ret < 0)
                        goto err_in_read;
-               ret = doc_read_page_getbytes(docg3, readlen, buf, 1);
-               if (ret < readlen)
+               ret = doc_read_page_getbytes(docg3, nbdata, buf, 1);
+               if (ret < nbdata)
                        goto err_in_read;
-               ret = doc_read_page_getbytes(docg3, DOC_LAYOUT_OOB_SIZE,
-                                            oob, 0);
-               if (ret < DOC_LAYOUT_OOB_SIZE)
+               doc_read_page_getbytes(docg3, DOC_LAYOUT_PAGE_SIZE - nbdata,
+                                      NULL, 0);
+               ret = doc_read_page_getbytes(docg3, nboob, oobbuf, 0);
+               if (ret < nboob)
                        goto err_in_read;
+               doc_read_page_getbytes(docg3, DOC_LAYOUT_OOB_SIZE - nboob,
+                                      NULL, 0);
 
-               *retlen += readlen;
-               buf += readlen;
-               len -= readlen;
-
-               ofs ^= DOC_LAYOUT_PAGE_OOB_SIZE;
-               if (ofs == 0)
-                       page += 2;
-               if (page > DOC_ADDR_PAGE_MASK) {
-                       page = 0;
-                       block0 += 2;
-                       block1 += 2;
-               }
-
-               /*
-                * There should be a BCH bitstream fixing algorithm here ...
-                * By now, a page read failure is triggered by BCH error
-                */
-               doc_get_hw_bch_syndroms(docg3, syn);
+               doc_get_hw_bch_syndroms(docg3, calc_ecc);
                eccconf1 = doc_register_readb(docg3, DOC_ECCCONF1);
 
-               doc_dbg("OOB - INFO: %02x:%02x:%02x:%02x:%02x:%02x:%02x\n",
-                        oob[0], oob[1], oob[2], oob[3], oob[4],
-                        oob[5], oob[6]);
-               doc_dbg("OOB - HAMMING: %02x\n", oob[7]);
-               doc_dbg("OOB - BCH_ECC: %02x:%02x:%02x:%02x:%02x:%02x:%02x\n",
-                        oob[8], oob[9], oob[10], oob[11], oob[12],
-                        oob[13], oob[14]);
-               doc_dbg("OOB - UNUSED: %02x\n", oob[15]);
+               if (nboob >= DOC_LAYOUT_OOB_SIZE) {
+                       doc_dbg("OOB - INFO: %02x:%02x:%02x:%02x:%02x:%02x:%02x\n",
+                               oobbuf[0], oobbuf[1], oobbuf[2], oobbuf[3],
+                               oobbuf[4], oobbuf[5], oobbuf[6]);
+                       doc_dbg("OOB - HAMMING: %02x\n", oobbuf[7]);
+                       doc_dbg("OOB - BCH_ECC: %02x:%02x:%02x:%02x:%02x:%02x:%02x\n",
+                               oobbuf[8], oobbuf[9], oobbuf[10], oobbuf[11],
+                               oobbuf[12], oobbuf[13], oobbuf[14]);
+                       doc_dbg("OOB - UNUSED: %02x\n", oobbuf[15]);
+               }
                doc_dbg("ECC checks: ECCConf1=%x\n", eccconf1);
-               doc_dbg("ECC BCH syndrom: %02x:%02x:%02x:%02x:%02x:%02x:%02x\n",
-                       syn[0], syn[1], syn[2], syn[3], syn[4], syn[5], syn[6]);
+               doc_dbg("ECC CALC_ECC: %02x:%02x:%02x:%02x:%02x:%02x:%02x\n",
+                       calc_ecc[0], calc_ecc[1], calc_ecc[2],
+                       calc_ecc[3], calc_ecc[4], calc_ecc[5],
+                       calc_ecc[6]);
 
                ret = -EBADMSG;
                if (block0 >= DOC_LAYOUT_BLOCK_FIRST_DATA) {
-                       if (eccconf1 & DOC_ECCCONF1_BCH_SYNDROM_ERR)
+                       if ((eccconf1 & DOC_ECCCONF1_BCH_SYNDROM_ERR) &&
+                           (eccconf1 & DOC_ECCCONF1_PAGE_IS_WRITTEN))
                                goto err_in_read;
                        if (is_prot_seq_error(docg3))
                                goto err_in_read;
                }
+
                doc_read_page_finish(docg3);
+               ops->retlen += nbdata;
+               ops->oobretlen += nboob;
+               buf += nbdata;
+               oobbuf += nboob;
+               len -= nbdata;
+               ooblen -= nboob;
+               from += DOC_LAYOUT_PAGE_SIZE;
        }
 
        return 0;
@@ -642,54 +659,33 @@ err:
 }
 
 /**
- * doc_read_oob - Read out of band bytes from flash
+ * doc_read - Read bytes from flash
  * @mtd: the device
  * @from: the offset from first block and first page, in bytes, aligned on page
  *        size
- * @ops: the mtd oob structure
+ * @len: the number of bytes to read (must be a multiple of 4)
+ * @retlen: the number of bytes actually read
+ * @buf: the filled in buffer
  *
- * Reads flash memory OOB area of pages.
+ * Reads flash memory pages. This function does not read the OOB chunk, but only
+ * the page data.
  *
  * Returns 0 if read successfull, of -EIO, -EINVAL if an error occured
  */
-static int doc_read_oob(struct mtd_info *mtd, loff_t from,
-                       struct mtd_oob_ops *ops)
+static int doc_read(struct mtd_info *mtd, loff_t from, size_t len,
+            size_t *retlen, u_char *buf)
 {
-       struct docg3 *docg3 = mtd->priv;
-       int block0, block1, page, ofs, ret;
-       u8 *buf = ops->oobbuf;
-       size_t len = ops->ooblen;
+       struct mtd_oob_ops ops;
+       size_t ret;
 
-       doc_dbg("doc_read_oob(from=%lld, buf=%p, len=%zu)\n", from, buf, len);
-       if (len != DOC_LAYOUT_OOB_SIZE)
-               return -EINVAL;
+       memset(&ops, 0, sizeof(ops));
+       ops.datbuf = buf;
+       ops.len = len;
+       ops.mode = MTD_OPS_AUTO_OOB;
 
-       switch (ops->mode) {
-       case MTD_OPS_PLACE_OOB:
-               buf += ops->ooboffs;
-               break;
-       default:
-               break;
-       }
-
-       calc_block_sector(from, &block0, &block1, &page, &ofs);
-       if (block1 > docg3->max_block)
-               return -EINVAL;
-
-       ret = doc_read_page_prepare(docg3, block0, block1, page,
-                                   ofs + DOC_LAYOUT_PAGE_SIZE);
-       if (!ret)
-               ret = doc_read_page_ecc_init(docg3, DOC_LAYOUT_OOB_SIZE);
-       if (!ret)
-               ret = doc_read_page_getbytes(docg3, DOC_LAYOUT_OOB_SIZE,
-                                            buf, 1);
-       doc_read_page_finish(docg3);
-
-       if (ret > 0)
-               ops->oobretlen = ret;
-       else
-               ops->oobretlen = 0;
-       return (ret > 0) ? 0 : ret;
+       ret = doc_read_oob(mtd, from, &ops);
+       *retlen = ops.retlen;
+       return ret;
 }
 
 static int doc_reload_bbt(struct docg3 *docg3)