If the architecture can't remap or set an address uncached there is no way
to fullfill a request for a coherent allocation. Return NULL in that case.
Note that this case currently does not happen, so this is a theoretical
fixup and/or a preparation for eventually supporting platforms that
can't support coherent allocations with the generic code.
Signed-off-by: Christoph Hellwig <h...@lst.de>
---
kernel/dma/direct.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)
diff --git a/kernel/dma/direct.c b/kernel/dma/direct.c
index f9658fe18498c..a13017656ecae 100644
--- a/kernel/dma/direct.c
+++ b/kernel/dma/direct.c
@@ -233,8 +233,9 @@ void *dma_direct_alloc(struct device *dev, size_t size,
return dma_direct_alloc_from_pool(dev, size,
dma_handle, gfp);
} else {
- if (IS_ENABLED(CONFIG_ARCH_HAS_DMA_SET_UNCACHED))
- set_uncached = true;
+ if (!IS_ENABLED(CONFIG_ARCH_HAS_DMA_SET_UNCACHED))
+ return NULL;
+ set_uncached = true;
}
}
--
2.30.2
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