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authorPierre Ossman <drzeus-list@drzeus.cx>2006-09-07 11:01:30 -0400
committerRussell King <rmk+kernel@arm.linux.org.uk>2006-09-07 11:01:30 -0400
commit6fe9febb8af2f82f9caace1aa1c00cd8de7469ac (patch)
tree32af472c52ab5cfabe1a974fe1df92c164a337da /drivers/mmc/mmc_block.c
parentd773d7255199a6c8934e197756f54a1115dd127b (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/mmc/mmc_block.c')
-rw-r--r--drivers/mmc/mmc_block.c49
1 files changed, 4 insertions, 45 deletions
diff --git a/drivers/mmc/mmc_block.c b/drivers/mmc/mmc_block.c
index d6fcc467b503..a0e0dad1b419 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)
319 md->read_only = mmc_blk_readonly(card); 319 md->read_only = mmc_blk_readonly(card);
320 320
321 /* 321 /*
322 * Figure out a workable block size. MMC cards have: 322 * Both SD and MMC specifications state (although a bit
323 * - two block sizes, one for read and one for write. 323 * unclearly in the MMC case) that a block size of 512
324 * - may support partial reads and/or writes 324 * bytes must always be supported by the card.
325 * (allows block sizes smaller than specified)
326 */ 325 */
327 md->block_bits = card->csd.read_blkbits; 326 md->block_bits = 9;
328 if (card->csd.write_blkbits != card->csd.read_blkbits) {
329 if (card->csd.write_blkbits < card->csd.read_blkbits &&
330 card->csd.read_partial) {
331 /*
332 * write block size is smaller than read block
333 * size, but we support partial reads, so choose
334 * the smaller write block size.
335 */
336 md->block_bits = card->csd.write_blkbits;
337 } else if (card->csd.write_blkbits > card->csd.read_blkbits &&
338 card->csd.write_partial) {
339 /*
340 * read block size is smaller than write block
341 * size, but we support partial writes. Use read
342 * block size.
343 */
344 } else {
345 /*
346 * We don't support this configuration for writes.
347 */
348 printk(KERN_ERR "%s: unable to select block size for "
349 "writing (rb%u wb%u rp%u wp%u)\n",
350 mmc_card_id(card),
351 1 << card->csd.read_blkbits,
352 1 << card->csd.write_blkbits,
353 card->csd.read_partial,
354 card->csd.write_partial);
355 md->read_only = 1;
356 }
357 }
358
359 /*
360 * Refuse to allow block sizes smaller than 512 bytes.
361 */
362 if (md->block_bits < 9) {
363 printk(KERN_ERR "%s: unable to support block size %u\n",
364 mmc_card_id(card), 1 << md->block_bits);
365 ret = -EINVAL;
366 goto err_kfree;
367 }
368 327
369 md->disk = alloc_disk(1 << MMC_SHIFT); 328 md->disk = alloc_disk(1 << MMC_SHIFT);
370 if (md->disk == NULL) { 329 if (md->disk == NULL) {