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Speed optimisations: (1) Read, write: Use single/multiple block commands depending on the block count. (2) Write: Combine first partial sector transfer (after caching) & main loop into one block-transfer sequence.

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git-svn-id: svn://svn.rockbox.org/rockbox/trunk@6381 a1c6a512-1295-4272-9138-f99709370657
This commit is contained in:
Jens Arnold 2005-04-28 20:47:55 +00:00
parent 238bea7370
commit 74875ef37e
1 changed files with 81 additions and 62 deletions
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143
firmware/drivers/ata_mmc.c
View file

@ -744,16 +744,19 @@ int ata_read_sectors(IF_MV2(int drive,)
c_addr += len;
c_block++;
}
/* some cards don't like reading the very last sector with
* CMD_READ_MULTIPLE_BLOCK, so make sure this sector is always
* read with CMD_READ_SINGLE_BLOCK. This is caught by the 'last
* partial block' read. */
/* some cards don't like reading the very last block with
* CMD_READ_MULTIPLE_BLOCK, so make sure this block is always
* read with CMD_READ_SINGLE_BLOCK. Let the 'last partial block'
* read catch this. */
if (c_end_block == card->numblocks)
c_end_block--;
if (c_block < c_end_block)
{
rc = send_cmd(CMD_READ_MULTIPLE_BLOCK, c_addr, &response);
int read_cmd = (c_end_block - c_block > 1) ?
CMD_READ_MULTIPLE_BLOCK : CMD_READ_SINGLE_BLOCK;
rc = send_cmd(read_cmd, c_addr, &response);
if (rc)
{
rc = rc * 10 - 4;
@ -774,11 +777,14 @@ int ata_read_sectors(IF_MV2(int drive,)
c_addr += blocksize;
c_block++;
}
rc = send_cmd(CMD_STOP_TRANSMISSION, 0, &response);
if (rc)
if (read_cmd == CMD_READ_MULTIPLE_BLOCK)
{
rc = rc * 10 - 6;
goto error;
rc = send_cmd(CMD_STOP_TRANSMISSION, 0, &response);
if (rc)
{
rc = rc * 10 - 6;
goto error;
}
}
bitswap(inbuf_prev, blocksize);
}
@ -848,81 +854,94 @@ int ata_write_sectors(IF_MV2(int drive,)
offset = c_addr & (blocksize - 1);
c_block = c_addr >> card->block_exp;
c_end_block = c_end_addr >> card->block_exp;
if (offset) /* first partial block */
{
unsigned long len = MIN(c_end_addr - c_addr, blocksize - offset);
rc = cache_block(IF_MV2(drive,) c_block, blocksize,
card->read_timeout);
if (rc)
/* Special case: first block is trimmed at both ends. May only happen
* if (blocksize > 2 * sectorsize), i.e. blocksize == 2048 */
if ((c_block == c_end_block) && offset)
c_end_block++;
if (c_block < c_end_block)
{
int write_cmd;
unsigned char start_token;
if (c_end_block - c_block > 1)
{
rc = rc * 10 - 2;
goto error;
write_cmd = CMD_WRITE_MULTIPLE_BLOCK;
start_token = DT_START_WRITE_MULTIPLE;
}
swapcopy(block_cache[current_cache].data + 2 + offset, buf, len);
rc = send_cmd(CMD_WRITE_BLOCK, c_addr - offset, &response);
else
{
write_cmd = CMD_WRITE_BLOCK;
start_token = DT_START_BLOCK;
}
if (offset)
{
unsigned long len = MIN(c_end_addr - c_addr, blocksize - offset);
rc = cache_block(IF_MV2(drive,) c_block, blocksize,
card->read_timeout);
if (rc)
{
rc = rc * 10 - 2;
goto error;
}
swapcopy(block_cache[current_cache].data + 2 + offset, buf, len);
buf += len;
c_addr -= offset;
}
else
{
swapcopy_block(buf, blocksize);
buf += blocksize;
}
rc = send_cmd(write_cmd, c_addr, &response);
if (rc)
{
rc = rc * 10 - 3;
goto error;
}
buf += len;
rc = send_block(NULL, blocksize, DT_START_BLOCK, card->write_timeout);
if (rc)
c_block++; /* early increment to simplify the loop */
while (c_block < c_end_block)
{
rc = rc * 10 - 4;
goto error;
rc = send_block(buf, blocksize, start_token, card->write_timeout);
if (rc)
{
rc = rc * 10 - 4;
goto error;
}
last_disk_activity = current_tick;
buf += blocksize;
c_addr += blocksize;
c_block++;
}
c_addr += len;
c_block++;
}
if (c_block < c_end_block)
{
swapcopy_block(buf, blocksize);
rc = send_cmd(CMD_WRITE_MULTIPLE_BLOCK, c_addr, &response);
rc = send_block(NULL, blocksize, start_token, card->write_timeout);
if (rc)
{
rc = rc * 10 - 5;
goto error;
}
while (c_block < c_end_block - 1)
{
buf += blocksize;
rc = send_block(buf, blocksize, DT_START_WRITE_MULTIPLE,
card->write_timeout);
if (rc)
{
rc = rc * 10 - 6;
goto error;
}
last_disk_activity = current_tick;
c_addr += blocksize;
c_block++;
}
buf += blocksize;
rc = send_block(NULL, blocksize, DT_START_WRITE_MULTIPLE,
card->write_timeout);
if (rc)
{
rc = rc * 10 - 7;
goto error;
}
last_disk_activity = current_tick;
c_addr += blocksize;
c_block++;
response = DT_STOP_TRAN;
write_transfer(&response, 1);
poll_busy(card->write_timeout);
/* c_block++ was done early */
if (write_cmd == CMD_WRITE_MULTIPLE_BLOCK)
{
response = DT_STOP_TRAN;
write_transfer(&response, 1);
poll_busy(card->write_timeout);
}
}
if (c_addr < c_end_addr) /* last partial block */
{
rc = cache_block(IF_MV2(drive,) c_block, blocksize,
card->read_timeout);
if (rc)
{
rc = rc * 10 - 8;
rc = rc * 10 - 6;
goto error;
}
swapcopy(block_cache[current_cache].data + 2, buf,
@ -930,13 +949,13 @@ int ata_write_sectors(IF_MV2(int drive,)
rc = send_cmd(CMD_WRITE_BLOCK, c_addr, &response);
if (rc)
{
rc = rc * 10 - 9;
rc = rc * 10 - 7;
goto error;
}
rc = send_block(NULL, blocksize, DT_START_BLOCK, card->write_timeout);
if (rc)
{
rc = rc * 10 - 9;
rc = rc * 10 - 8;
goto error;
}
}