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authorRalf Baechle <ralf@linux-mips.org>2014-11-11 22:22:03 +0100
committerRalf Baechle <ralf@linux-mips.org>2014-11-24 07:45:08 +0100
commit0dc294c05d9df09ca4a65071e370247eaab8638d (patch)
tree2310d36d1f94bc24057dba1451e3dffc40099094
parent341097f17c76b3dd39539526a2af9e7fff43705e (diff)
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MIPS: DMA: Explain the lack of special handling for R14000/R16000.
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
-rw-r--r--arch/mips/mm/dma-default.c5
1 files changed, 5 insertions, 0 deletions
diff --git a/arch/mips/mm/dma-default.c b/arch/mips/mm/dma-default.c
index 33ba3c558fe4..af5f046e627e 100644
--- a/arch/mips/mm/dma-default.c
+++ b/arch/mips/mm/dma-default.c
@@ -61,6 +61,11 @@ static inline struct page *dma_addr_to_page(struct device *dev,
* Warning on the terminology - Linux calls an uncached area coherent;
* MIPS terminology calls memory areas with hardware maintained coherency
* coherent.
+ *
+ * Note that the R14000 and R16000 should also be checked for in this
+ * condition. However this function is only called on non-I/O-coherent
+ * systems and only the R10000 and R12000 are used in such systems, the
+ * SGI IP28 Indigo² rsp. SGI IP32 aka O2.
*/
static inline int cpu_needs_post_dma_flush(struct device *dev)
{
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