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Diffstat (limited to 'common/cmd_ace.c')
-rw-r--r--common/cmd_ace.c68
1 files changed, 47 insertions, 21 deletions
diff --git a/common/cmd_ace.c b/common/cmd_ace.c
index 555fbe3..b6f8604 100644
--- a/common/cmd_ace.c
+++ b/common/cmd_ace.c
@@ -121,6 +121,7 @@ static unsigned long systemace_read(int dev,
{
unsigned val;
int retry;
+ unsigned blk_countdown;
unsigned char*dp = (unsigned char*)buffer;
if (get_cf_lock() < 0) {
@@ -136,6 +137,10 @@ static unsigned long systemace_read(int dev,
return 0;
}
+#ifdef DEBUG_SYSTEMACE
+ printf("... systemace read %lu sectors at %lu\n", blkcnt, start);
+#endif
+
retry = 2000;
for (;;) {
unsigned val = ace_readw(0x04);
@@ -161,34 +166,55 @@ static unsigned long systemace_read(int dev,
retry -= 1;
}
- /* Write LBA block address */
- ace_writew(start & 0xffff, 0x10);
- start >>= 16;
- ace_writew(start & 0xff, 0x12);
+ /* The SystemACE can only transfer 256 sectors at a time, so
+ limit the current chunk of sectors. The blk_countdown
+ variable is the number of sectors left to transfer. */
- /* Write sector count | ReadMemCardData. */
- ace_writew(blkcnt | 0x0300, 0x14);
+ blk_countdown = blkcnt;
+ while (blk_countdown > 0) {
+ unsigned trans = blk_countdown;
- /* CONTROLREG = CFGRESET|LOCKREQ */
- ace_writew(0x0082, 0x18);
+ if (trans > 256) trans = 256;
- retry = blkcnt * 16;
- while (retry > 0) {
- int idx;
+#ifdef DEBUG_SYSTEMACE
+ printf("... transfer %lu sector in a chunk\n", trans);
+#endif
+ /* Write LBA block address */
+ ace_writew((start>> 0) & 0xffff, 0x10);
+ ace_writew((start>>16) & 0x00ff, 0x12);
- /* Wait for buffer to become ready. */
- while (! (ace_readw(0x04) & 0x0020)) {
- udelay(1000);
- }
+ /* NOTE: in the Write Sector count below, a count of 0
+ causes a transfer of 256, so &0xff gives the right
+ value for whatever transfer count we want. */
+
+ /* Write sector count | ReadMemCardData. */
+ ace_writew((trans&0xff) | 0x0300, 0x14);
- /* Read 16 words of 2bytes from the sector buffer. */
- for (idx = 0 ; idx < 16 ; idx += 1) {
- unsigned short val = ace_readw(0x40);
- *dp++ = val & 0xff;
- *dp++ = (val>>8) & 0xff;
+ /* CONTROLREG = CFGRESET|LOCKREQ */
+ ace_writew(0x0082, 0x18);
+
+ retry = trans * 16;
+ while (retry > 0) {
+ int idx;
+
+ /* Wait for buffer to become ready. */
+ while (! (ace_readw(0x04) & 0x0020)) {
+ udelay(1000);
+ }
+
+ /* Read 16 words of 2bytes from the sector buffer. */
+ for (idx = 0 ; idx < 16 ; idx += 1) {
+ unsigned short val = ace_readw(0x40);
+ *dp++ = val & 0xff;
+ *dp++ = (val>>8) & 0xff;
+ }
+
+ retry -= 1;
}
- retry -= 1;
+ /* Count the blocks we transfer this time. */
+ start += trans;
+ blk_countdown -= trans;
}
release_cf_lock();