Don't just check for a swiotlb buffer, but also if buffering might
be required for this particular device.
Fixes: 133d624b1cee ("dma: Introduce dma_max_mapping_size()")
Reported-by: Benjamin Herrenschmidt <[email protected]>
Signed-off-by: Christoph Hellwig <[email protected]>
Tested-by: Benjamin Herrenschmidt <[email protected]>
---
kernel/dma/direct.c | 10 ++++------
1 file changed, 4 insertions(+), 6 deletions(-)
diff --git a/kernel/dma/direct.c b/kernel/dma/direct.c
index d7cec866d16b..e269b6f9b444 100644
--- a/kernel/dma/direct.c
+++ b/kernel/dma/direct.c
@@ -399,11 +399,9 @@ int dma_direct_supported(struct device *dev, u64 mask)
size_t dma_direct_max_mapping_size(struct device *dev)
{
- size_t size = SIZE_MAX;
-
/* If SWIOTLB is active, use its maximum mapping size */
- if (is_swiotlb_active())
- size = swiotlb_max_mapping_size(dev);
-
- return size;
+ if (is_swiotlb_active() &&
+ (dma_addressing_limited(dev) || swiotlb_force == SWIOTLB_FORCE))
+ return swiotlb_max_mapping_size(dev);
+ return SIZE_MAX;
}
--
2.20.1
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