Re: [PATCH] ieee1394: sbp2: enforce 32bit DMA mapping

[Stefan Richter <stefanr@s5r6.in-berlin.de>]

David Moore wrote:
> Yes, I think you should use GFP_DMA32 instead of GFP_DMA.  GFP_DMA
> refers to just the first 16MB of memory.

Yes, I forgot that GFP_DMA is for ISA DMA. However since GFP_DMA32 is
nowhere enforced except in allocations for coherent PCI DMA and in some
AGP code I think now I'll just drop that hunk.


From: Stefan Richter <stefanr@s5r6.in-berlin.de>
Subject: ieee1394: sbp2: enforce 32bit DMA mapping

In order to use OHCI-1394 physical DMA, all s/g elements, s/g tables,
ORBs, and response buffers have to reside within the first 4 GB of the
FireWire controller's physical address space.

Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
---
Index: linux-2.6.20-rc5/drivers/ieee1394/sbp2.c
===================================================================
--- linux-2.6.20-rc5.orig/drivers/ieee1394/sbp2.c
+++ linux-2.6.20-rc5/drivers/ieee1394/sbp2.c
@@ -757,6 +757,11 @@ static struct sbp2_lu *sbp2_alloc_device
 			SBP2_ERR("failed to register lower 4GB address range");
 			goto failed_alloc;
 		}
+#else
+		if (dma_set_mask(hi->host->device.parent, DMA_32BIT_MASK)) {
+			SBP2_ERR("failed to set 4GB DMA mask");
+			goto failed_alloc;
+		}
 #endif
 	}
 

-- 
Stefan Richter
-=====-=-=== --=- --=--
http://arcgraph.de/sr/


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