path: root/lib/dma-debug.c
diff options
authorKrzysztof Halasa <khc@pm.waw.pl>2010-01-08 22:42:36 (GMT)
committerLinus Torvalds <torvalds@linux-foundation.org>2010-01-11 17:34:04 (GMT)
commit42d53b4ff7d61487d18274ebdf1f70c1aef6f122 (patch)
tree55ef141c2c6e9ef52c724dd6aec03a8708d288b1 /lib/dma-debug.c
parente992cd9b72a18122bd5c958715623057f110793f (diff)
dma-debug: allow DMA_BIDIRECTIONAL mappings to be synced with DMA_FROM_DEVICE and
There is no need to perform full BIDIR sync (copying the buffers in case of swiotlb and similar schemes) if we know that the owner (CPU or device) hasn't altered the data. Addresses the false-positive reported at http://bugzilla.kernel.org/show_bug.cgi?id=14169 Signed-off-by: Krzysztof Halasa <khc@pm.waw.pl> Cc: David Miller <davem@davemloft.net> Cc: Joerg Roedel <joerg.roedel@amd.com> Cc: <stable@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'lib/dma-debug.c')
1 files changed, 3 insertions, 4 deletions
diff --git a/lib/dma-debug.c b/lib/dma-debug.c
index cf90620..7d2f0b3 100644
--- a/lib/dma-debug.c
+++ b/lib/dma-debug.c
@@ -913,6 +913,9 @@ static void check_sync(struct device *dev,
+ if (entry->direction == DMA_BIDIRECTIONAL)
+ goto out;
if (ref->direction != entry->direction) {
err_printk(dev, entry, "DMA-API: device driver syncs "
"DMA memory with different direction "
@@ -923,9 +926,6 @@ static void check_sync(struct device *dev,
- if (entry->direction == DMA_BIDIRECTIONAL)
- goto out;
if (to_cpu && !(entry->direction == DMA_FROM_DEVICE) &&
!(ref->direction == DMA_TO_DEVICE))
err_printk(dev, entry, "DMA-API: device driver syncs "
@@ -948,7 +948,6 @@ static void check_sync(struct device *dev,
put_hash_bucket(bucket, &flags);
void debug_dma_map_page(struct device *dev, struct page *page, size_t offset,

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