dma-debug: add comment for failed to check map error

Add comment for failure to check a map error to help driver developers.

Link: http://lkml.kernel.org/r/1484622289-22085-1-git-send-email-miles.chen@mediatek.com
Signed-off-by: Miles Chen <miles.chen@mediatek.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Miles Chen 2017-02-22 15:40:09 -08:00 committed by Linus Torvalds
parent f42003917b
commit a5759b2bff

View File

@ -1155,6 +1155,11 @@ static void check_unmap(struct dma_debug_entry *ref)
dir2name[ref->direction]);
}
/*
* Drivers should use dma_mapping_error() to check the returned
* addresses of dma_map_single() and dma_map_page().
* If not, print this warning message. See Documentation/DMA-API.txt.
*/
if (entry->map_err_type == MAP_ERR_NOT_CHECKED) {
err_printk(ref->dev, entry,
"DMA-API: device driver failed to check map error"