[PATCH] fix of_parse_dma_window. was: Re: [PATCH 1/2] powerpc: Add of_parse_dma_window()

[Will Schmidt]

On Thu, 2006-05-18 at 18:13 -0500, Olof Johansson wrote:
> On Fri, May 19, 2006 at 01:11:51AM +0200, Segher Boessenkool wrote:
> > > Acked-by: Olof Johansson <olof at lixom.net>
> > >
> > > (I'm assuming you've booted it on POWER4 LPAR and JS20, I don't
> > > have access to either to make sure it doesn't break there. Main worry
> > > would be if it lacked ibm,#dma*-properties for some reason.)
> > 
> > The code seems to be resilient against that.  Haven't tested though.
> 
> Well, yes. I should have said: if it lacks the ibm,#dma- and the
> normal addr-cells properties aren't the same as we assumed before.

My js20 appears to lack the ibm,#dma- properties, and boot fails with a
"Kernel panic - not syncing: iommu_init_table: Can't allocate 0 bytes"
message.  

This adds a fallback to the "#address-cells" property in case the
"#ibm,dma-address-cells" property is missing.   Tested on js20 and
power5 lpar.  

Unless there is a more elegant solution... :-)

Signed-off-by: Will Schmidt <willschm at us.ibm.com>


diff --git a/arch/powerpc/kernel/prom_parse.c b/arch/powerpc/kernel/prom_parse.c
index 23bb060..45df420 100644
--- a/arch/powerpc/kernel/prom_parse.c
+++ b/arch/powerpc/kernel/prom_parse.c
@@ -561,6 +561,9 @@ void of_parse_dma_window(struct device_n
 	*busno = *(dma_window++);
 
 	prop = get_property(dn, "ibm,#dma-address-cells", NULL);
+	if (!prop)
+		prop = get_property(dn, "#address-cells", NULL);
+
 	cells = prop ? *(u32 *)prop : prom_n_addr_cells(dn);
 	*phys = of_read_addr(dma_window, cells);