lkml.org 
[lkml]   [2011]   [Nov]   [19]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH v3 05/16] mtd/docg3: fix reading oob+data without correction
Date
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>
---
drivers/mtd/devices/docg3.c | 194 +++++++++++++++++++++----------------------
1 files changed, 95 insertions(+), 99 deletions(-)
diff --git a/drivers/mtd/devices/docg3.c b/drivers/mtd/devices/docg3.c
index 5834e6e..1c2f54d 100644
--- a/drivers/mtd/devices/docg3.c
+++ b/drivers/mtd/devices/docg3.c
@@ -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)
--
1.7.5.4


\
 
 \ /
  Last update: 2011-11-19 16:05    [from the cache]
©2003-2011 Jasper Spaans