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author | Adrian Hunter <ext-adrian.hunter@nokia.com> | 2007-01-04 09:51:26 +0200 |
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committer | Artem Bityutskiy <dedekind@infradead.org> | 2007-01-10 14:58:42 +0200 |
commit | a8de85d557004d6d4e4cf79ecd6b97339b986fe9 (patch) | |
tree | 02b3b1dfef5dd1f0e197c2584baff302ca6b6fd6 /drivers | |
parent | 2fd32d4af83f4535d12d3f6dd23189352a9596fa (diff) | |
download | kernel_samsung_smdk4412-a8de85d557004d6d4e4cf79ecd6b97339b986fe9.zip kernel_samsung_smdk4412-a8de85d557004d6d4e4cf79ecd6b97339b986fe9.tar.gz kernel_samsung_smdk4412-a8de85d557004d6d4e4cf79ecd6b97339b986fe9.tar.bz2 |
[MTD] OneNAND: Implement read-while-load
Read-while-load enables higher performance read operations.
Signed-off-by: Adrian Hunter <ext-adrian.hunter@nokia.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Diffstat (limited to 'drivers')
-rw-r--r-- | drivers/mtd/onenand/onenand_base.c | 74 |
1 files changed, 42 insertions, 32 deletions
diff --git a/drivers/mtd/onenand/onenand_base.c b/drivers/mtd/onenand/onenand_base.c index e80857b..abbe160 100644 --- a/drivers/mtd/onenand/onenand_base.c +++ b/drivers/mtd/onenand/onenand_base.c @@ -727,40 +727,47 @@ static int onenand_read(struct mtd_info *mtd, loff_t from, size_t len, /* TODO handling oob */ stats = mtd->ecc_stats; - while (read < len) { - cond_resched(); - - thislen = min_t(int, mtd->writesize, len - read); - - column = from & (mtd->writesize - 1); - if (column + thislen > mtd->writesize) - thislen = mtd->writesize - column; - - if (!onenand_check_bufferram(mtd, from)) { - this->command(mtd, ONENAND_CMD_READ, from, mtd->writesize); - - ret = this->wait(mtd, FL_READING); - /* First copy data and check return value for ECC handling */ - onenand_update_bufferram(mtd, from, !ret); - } - - this->read_bufferram(mtd, ONENAND_DATARAM, buf, column, thislen); - if (ret) { - DEBUG(MTD_DEBUG_LEVEL0, "onenand_read: read failed = %d\n", ret); - goto out; - } + /* Read-while-load method */ + + /* Do first load to bufferRAM */ + if (read < len) { + if (!onenand_check_bufferram(mtd, from)) { + this->command(mtd, ONENAND_CMD_READ, from, mtd->writesize); + ret = this->wait(mtd, FL_READING); + onenand_update_bufferram(mtd, from, !ret); + } + } + + thislen = min_t(int, mtd->writesize, len - read); + column = from & (mtd->writesize - 1); + if (column + thislen > mtd->writesize) + thislen = mtd->writesize - column; + + while (!ret) { + /* If there is more to load then start next load */ + from += thislen; + if (read + thislen < len) { + this->command(mtd, ONENAND_CMD_READ, from, mtd->writesize); + ONENAND_SET_PREV_BUFFERRAM(this); + } + /* While load is going, read from last bufferRAM */ + this->read_bufferram(mtd, ONENAND_DATARAM, buf, column, thislen); + /* See if we are done */ + read += thislen; + if (read == len) + break; + /* Set up for next read from bufferRAM */ + ONENAND_SET_NEXT_BUFFERRAM(this); + buf += thislen; + thislen = min_t(int, mtd->writesize, len - read); + column = 0; + cond_resched(); + /* Now wait for load */ + ret = this->wait(mtd, FL_READING); + onenand_update_bufferram(mtd, from, !ret); + } - read += thislen; - - if (read == len) - break; - - from += thislen; - buf += thislen; - } - -out: /* Deselect and wake up anyone waiting on the device */ onenand_release_device(mtd); @@ -774,6 +781,9 @@ out: if (mtd->ecc_stats.failed - stats.failed) return -EBADMSG; + if (ret) + return ret; + return mtd->ecc_stats.corrected - stats.corrected ? -EUCLEAN : 0; } |