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author | Aidan MacDonald <amachronic@protonmail.com> | 2021-05-13 15:29:02 +0100 |
---|---|---|
committer | Aidan MacDonald <amachronic@protonmail.com> | 2021-05-14 10:30:41 +0000 |
commit | eb0336ededda8d64b0f5fd98853b85ea5aa46060 (patch) | |
tree | 7570b0789ba8c2b6f85b2513b56a40d600af334c /firmware/drivers/fat.c | |
parent | ff28d238b8a9dd5a5e457387378428ca8e3c8ffd (diff) | |
download | rockbox-eb0336ededda8d64b0f5fd98853b85ea5aa46060.tar.gz rockbox-eb0336ededda8d64b0f5fd98853b85ea5aa46060.zip |
FAT: align writes when bounce buffering is enabled
Motivation: turns out the DMA in the M3K's MSC controller is buggy,
and can't handle unaligned addresses properly despite the HW docs
claiming otherwise.
Extending the FAT driver bounce buffering code is the easiest way
to work around the problem (but probably not the most efficient).
Change-Id: I1b59b0eb4bbc881d317ff10c64ecadb1f9041236
Diffstat (limited to 'firmware/drivers/fat.c')
-rw-r--r-- | firmware/drivers/fat.c | 57 |
1 files changed, 28 insertions, 29 deletions
diff --git a/firmware/drivers/fat.c b/firmware/drivers/fat.c index 50619983e9..337e29a1bc 100644 --- a/firmware/drivers/fat.c +++ b/firmware/drivers/fat.c | |||
@@ -2384,44 +2384,43 @@ static long transfer(struct bpb *fat_bpb, unsigned long start, long count, | |||
2384 | panicf("Write %ld after data\n", | 2384 | panicf("Write %ld after data\n", |
2385 | start + count - fat_bpb->totalsectors); | 2385 | start + count - fat_bpb->totalsectors); |
2386 | } | 2386 | } |
2387 | else | ||
2388 | { | ||
2389 | rc = storage_write_sectors(IF_MD(fat_bpb->drive,) | ||
2390 | start + fat_bpb->startsector, count, buf); | ||
2391 | } | ||
2392 | } | 2387 | } |
2393 | else | ||
2394 | { | ||
2395 | void* xferbuf = buf; | ||
2396 | #ifdef STORAGE_NEEDS_BOUNCE_BUFFER | ||
2397 | int remain = count; | ||
2398 | int xferred = 0; | ||
2399 | int aligned = 1; | ||
2400 | if(STORAGE_OVERLAP((uintptr_t)buf)) { | ||
2401 | xferbuf = FAT_BOUNCE_BUFFER(fat_bpb); | ||
2402 | aligned = 0; | ||
2403 | count = MIN(remain, FAT_BOUNCE_SECTORS); | ||
2404 | } | ||
2405 | 2388 | ||
2406 | while(remain > 0) { | ||
2407 | #endif | ||
2408 | rc = storage_read_sectors(IF_MD(fat_bpb->drive,) | ||
2409 | start + fat_bpb->startsector, count, xferbuf); | ||
2410 | #ifdef STORAGE_NEEDS_BOUNCE_BUFFER | 2389 | #ifdef STORAGE_NEEDS_BOUNCE_BUFFER |
2390 | if(UNLIKELY(STORAGE_OVERLAP((uintptr_t)buf))) { | ||
2391 | void* xfer_buf = FAT_BOUNCE_BUFFER(fat_bpb); | ||
2392 | while(count > 0) { | ||
2393 | int xfer_count = MIN(count, FAT_BOUNCE_SECTORS); | ||
2394 | |||
2395 | if(write) { | ||
2396 | memcpy(xfer_buf, buf, xfer_count * SECTOR_SIZE); | ||
2397 | rc = storage_write_sectors(IF_MD(fat_bpb->drive,) | ||
2398 | start + fat_bpb->startsector, xfer_count, xfer_buf); | ||
2399 | } else { | ||
2400 | rc = storage_read_sectors(IF_MD(fat_bpb->drive,) | ||
2401 | start + fat_bpb->startsector, xfer_count, xfer_buf); | ||
2402 | memcpy(buf, xfer_buf, xfer_count * SECTOR_SIZE); | ||
2403 | } | ||
2404 | |||
2411 | if(rc < 0) | 2405 | if(rc < 0) |
2412 | break; | 2406 | break; |
2413 | if(LIKELY(aligned)) | ||
2414 | break; | ||
2415 | 2407 | ||
2416 | memcpy(buf, xferbuf, count * SECTOR_SIZE); | 2408 | buf += xfer_count * SECTOR_SIZE; |
2417 | buf += count * SECTOR_SIZE; | 2409 | start += xfer_count; |
2418 | xferred += count; | 2410 | count -= xfer_count; |
2419 | start += count; | ||
2420 | remain -= count; | ||
2421 | count = MIN(remain, FAT_BOUNCE_SECTORS); | ||
2422 | } | 2411 | } |
2412 | } else { | ||
2423 | #endif | 2413 | #endif |
2414 | if(write) { | ||
2415 | rc = storage_write_sectors(IF_MD(fat_bpb->drive,) | ||
2416 | start + fat_bpb->startsector, count, buf); | ||
2417 | } else { | ||
2418 | rc = storage_read_sectors(IF_MD(fat_bpb->drive,) | ||
2419 | start + fat_bpb->startsector, count, buf); | ||
2420 | } | ||
2421 | #ifdef STORAGE_NEEDS_BOUNCE_BUFFER | ||
2424 | } | 2422 | } |
2423 | #endif | ||
2425 | 2424 | ||
2426 | if (rc < 0) | 2425 | if (rc < 0) |
2427 | { | 2426 | { |