parisc: Fix iodc and device path return values on old machines

Older machines may not fully initialize the return values when asking for IODC
and device path data when building the inventory.  Work around possible
firmware leaks by proper initialization of the variables.

Signed-off-by: Helge Deller <deller@gmx.de>

Author: hdeller

arch/parisc/kernel/drivers.c

@@ -995,6 +995,7 @@ static __init int qemu_print_iodc_data(struct device *lin_dev, void *data)
 	struct pdc_system_map_mod_info pdc_mod_info;
 	struct pdc_module_path mod_path;
 
+	memset(&iodc_data, 0, sizeof(iodc_data));
 	status = pdc_iodc_read(&count, hpa, 0,
 		&iodc_data, sizeof(iodc_data));
 	if (status != PDC_OK) {
@@ -1012,6 +1013,11 @@ static __init int qemu_print_iodc_data(struct device *lin_dev, void *data)
 
 	mod_index = 0;
 	do {
+		/* initialize device path for old machines */
+		memset(&mod_path, 0xff, sizeof(mod_path));
+		get_node_path(dev->dev.parent, &mod_path.path);
+		mod_path.path.mod = dev->hw_path;
+		memset(&pdc_mod_info, 0, sizeof(pdc_mod_info));
 		status = pdc_system_map_find_mods(&pdc_mod_info,
 				&mod_path, mod_index++);
 	} while (status == PDC_OK && pdc_mod_info.mod_addr != hpa);