swiotlb: fix unexpected swiotlb_alloc_coherent failures

The code refactoring by commit 0176adb ("swiotlb: refactor coherent buffer allocation") made swiotlb_alloc_buffer almost always failing due to a thinko: namely, the function evaluates the dma_coherent_ok call incorrectly and dealing as if it's invalid. This ends up with weird errors like iwlwifi probe failure or amdgpu screen flickering. This patch corrects the logic error. Bugzilla: https://bugzilla.suse.com/show_bug.cgi?id=1088658 Bugzilla: https://bugzilla.suse.com/show_bug.cgi?id=1088902 Fixes: 0176adb ("swiotlb: refactor coherent buffer allocation") Cc: <[email protected]> # v4.16+ Signed-off-by: Takashi Iwai <[email protected]> Signed-off-by: Christoph Hellwig <[email protected]>
vieko · Apr 10, 2018 · 9e7f06c · 9e7f06c
1 parent b284d4d
commit 9e7f06c
Showing 1 changed file with 1 addition and 1 deletion.
diff --git a/lib/swiotlb.c b/lib/swiotlb.c
@@ -719,7 +719,7 @@ swiotlb_alloc_buffer(struct device *dev, size_t size, dma_addr_t *dma_handle,
 		goto out_warn;
 
 	*dma_handle = __phys_to_dma(dev, phys_addr);
-	if (dma_coherent_ok(dev, *dma_handle, size))
+	if (!dma_coherent_ok(dev, *dma_handle, size))
 		goto out_unmap;
 
 	memset(phys_to_virt(phys_addr), 0, size);