sparc: Fix bus type probing for ESP and LE devices.

If there is a dummy "espdma" or "ledma" parent device above ESP scsi
or LE ethernet device nodes, we have to match the bus as SBUS.

Otherwise the address and size cell counts are wrong and we don't
calculate the final physical device resource values correctly at all.

Commit 5280267c1dddb8d413595b87dc406624bb497946 ("sparc: Fix handling
of LANCE and ESP parent nodes in of_device.c") was meant to fix this
problem, but that only influences the inner loop of
build_device_resources().  We need this logic to also kick in at the
beginning of build_device_resources() as well, when we make the first
attempt to determine the device's immediate parent bus type for 'reg'
property element extraction.

Based almost entirely upon a patch by Friedrich Oslage.

Tested-by: Meelis Roos <mroos@linux.ee>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 19 insertions, 2 deletions

diff --git a/arch/sparc/kernel/of_device_32.c b/arch/sparc/kernel/of_device_32.c
index 0a83bd737654..c8f14c1dc521 100644
--- a/arch/sparc/kernel/of_device_32.c
+++ b/arch/sparc/kernel/of_device_32.c
@@ -246,8 +246,25 @@ static unsigned long of_bus_pci_get_flags(const u32 *addr, unsigned long flags)
 
 static int of_bus_sbus_match(struct device_node *np)
 {
-	return !strcmp(np->name, "sbus") ||
-		!strcmp(np->name, "sbi");
+	struct device_node *dp = np;
+
+	while (dp) {
+		if (!strcmp(dp->name, "sbus") ||
+		    !strcmp(dp->name, "sbi"))
+			return 1;
+
+		/* Have a look at use_1to1_mapping().  We're trying
+		 * to match SBUS if that's the top-level bus and we
+		 * don't have some intervening real bus that provides
+		 * ranges based translations.
+		 */
+		if (of_find_property(dp, "ranges", NULL) != NULL)
+			break;
+
+		dp = dp->parent;
+	}
+
+	return 0;
 }
 
 static void of_bus_sbus_count_cells(struct device_node *child,