[PATCH] powerpc: fix of_parse_dma_window

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@us.ibm.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>

1 files changed, 3 insertions, 0 deletions

diff --git a/arch/powerpc/kernel/prom_parse.c b/arch/powerpc/kernel/prom_parse.c
index 23bb060330ef..45df420383cc 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_node *dn, unsigned char *dma_window_prop,
         *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);