diff options
| author | Pierre Ossman <drzeus-list@drzeus.cx> | 2006-09-07 16:01:30 +0100 |
|---|---|---|
| committer | Russell King <rmk+kernel@arm.linux.org.uk> | 2006-09-07 16:01:30 +0100 |
| commit | 6fe9febb8af2f82f9caace1aa1c00cd8de7469ac (patch) | |
| tree | 32af472c52ab5cfabe1a974fe1df92c164a337da /drivers | |
| parent | d773d7255199a6c8934e197756f54a1115dd127b (diff) | |
[MMC] Always use a sector size of 512 bytes
Both MMC and SD specifications specify (although a bit unclearly in
the MMC case) that a sector size of 512 bytes must always be
supported by the card.
Cards can report larger "native" size than this, and cards >= 2 GB
even must do so. Most other readers use 512 bytes even for these
cards. We should do the same to be compatible.
Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/mmc/mmc_block.c | 49 |
1 files changed, 4 insertions, 45 deletions
diff --git a/drivers/mmc/mmc_block.c b/drivers/mmc/mmc_block.c index d6fcc467b50..a0e0dad1b41 100644 --- a/drivers/mmc/mmc_block.c +++ b/drivers/mmc/mmc_block.c @@ -319,52 +319,11 @@ static struct mmc_blk_data *mmc_blk_alloc(struct mmc_card *card) md->read_only = mmc_blk_readonly(card); /* - * Figure out a workable block size. MMC cards have: - * - two block sizes, one for read and one for write. - * - may support partial reads and/or writes - * (allows block sizes smaller than specified) + * Both SD and MMC specifications state (although a bit + * unclearly in the MMC case) that a block size of 512 + * bytes must always be supported by the card. */ - md->block_bits = card->csd.read_blkbits; - if (card->csd.write_blkbits != card->csd.read_blkbits) { - if (card->csd.write_blkbits < card->csd.read_blkbits && - card->csd.read_partial) { - /* - * write block size is smaller than read block - * size, but we support partial reads, so choose - * the smaller write block size. - */ - md->block_bits = card->csd.write_blkbits; - } else if (card->csd.write_blkbits > card->csd.read_blkbits && - card->csd.write_partial) { - /* - * read block size is smaller than write block - * size, but we support partial writes. Use read - * block size. - */ - } else { - /* - * We don't support this configuration for writes. - */ - printk(KERN_ERR "%s: unable to select block size for " - "writing (rb%u wb%u rp%u wp%u)\n", - mmc_card_id(card), - 1 << card->csd.read_blkbits, - 1 << card->csd.write_blkbits, - card->csd.read_partial, - card->csd.write_partial); - md->read_only = 1; - } - } - - /* - * Refuse to allow block sizes smaller than 512 bytes. - */ - if (md->block_bits < 9) { - printk(KERN_ERR "%s: unable to support block size %u\n", - mmc_card_id(card), 1 << md->block_bits); - ret = -EINVAL; - goto err_kfree; - } + md->block_bits = 9; md->disk = alloc_disk(1 << MMC_SHIFT); if (md->disk == NULL) { |