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authorTejun Heo <tj@kernel.org>2013-01-23 09:31:01 -0800
committerTejun Heo <tj@kernel.org>2013-01-23 09:31:01 -0800
commitc14afb82ffff5903a701a9fb737ac20f36d1f755 (patch)
tree304dcc7b1d7b9a5f564f7e978228e61ef41fbef2 /Documentation/DMA-API.txt
parent0fdff3ec6d87856cdcc99e69cf42143fdd6c56b4 (diff)
parent1d8549085377674224bf30a368284c391a3ce40e (diff)
Merge branch 'master' into for-3.9-async
To receive f56c3196f251012de9b3ebaff55732a9074fdaae ("async: fix __lowest_in_progress()"). Signed-off-by: Tejun Heo <tj@kernel.org>
Diffstat (limited to 'Documentation/DMA-API.txt')
-rw-r--r--Documentation/DMA-API.txt12
1 files changed, 12 insertions, 0 deletions
diff --git a/Documentation/DMA-API.txt b/Documentation/DMA-API.txt
index 66bd97a95f1..78a6c569d20 100644
--- a/Documentation/DMA-API.txt
+++ b/Documentation/DMA-API.txt
@@ -678,3 +678,15 @@ out of dma_debug_entries. These entries are preallocated at boot. The number
of preallocated entries is defined per architecture. If it is too low for you
boot with 'dma_debug_entries=<your_desired_number>' to overwrite the
architectural default.
+
+void debug_dmap_mapping_error(struct device *dev, dma_addr_t dma_addr);
+
+dma-debug interface debug_dma_mapping_error() to debug drivers that fail
+to check dma mapping errors on addresses returned by dma_map_single() and
+dma_map_page() interfaces. This interface clears a flag set by
+debug_dma_map_page() to indicate that dma_mapping_error() has been called by
+the driver. When driver does unmap, debug_dma_unmap() checks the flag and if
+this flag is still set, prints warning message that includes call trace that
+leads up to the unmap. This interface can be called from dma_mapping_error()
+routines to enable dma mapping error check debugging.
+