diff options
| -rw-r--r-- | lib/dma-debug.c | 24 |
1 files changed, 19 insertions, 5 deletions
diff --git a/lib/dma-debug.c b/lib/dma-debug.c index d3e06a5e981e..d87a17a819d0 100644 --- a/lib/dma-debug.c +++ b/lib/dma-debug.c @@ -1085,13 +1085,27 @@ void debug_dma_mapping_error(struct device *dev, dma_addr_t dma_addr) ref.dev = dev; ref.dev_addr = dma_addr; bucket = get_hash_bucket(&ref, &flags); - entry = bucket_find_exact(bucket, &ref); - if (!entry) - goto out; + list_for_each_entry(entry, &bucket->list, list) { + if (!exact_match(&ref, entry)) + continue; + + /* + * The same physical address can be mapped multiple + * times. Without a hardware IOMMU this results in the + * same device addresses being put into the dma-debug + * hash multiple times too. This can result in false + * positives being reported. Therefore we implement a + * best-fit algorithm here which updates the first entry + * from the hash which fits the reference value and is + * not currently listed as being checked. + */ + if (entry->map_err_type == MAP_ERR_NOT_CHECKED) { + entry->map_err_type = MAP_ERR_CHECKED; + break; + } + } - entry->map_err_type = MAP_ERR_CHECKED; -out: put_hash_bucket(bucket, &flags); } EXPORT_SYMBOL(debug_dma_mapping_error); |