drivers/base/topology.c: In function 'topology_is_visible': drivers/base/topology.c:158:24: warning: unused variable 'dev' [-Wunused-variable] 158 | struct device *dev = kobj_to_dev(kobj); This is because the topology_ppin(dev->id) macro expands to: (cpu_data(dev->id).ppin) and with CONFIG_SMP=n the cpu_data() macro expands to boot_cpu_data (ignoring its argument) with the end result: boot_cpu_data.ppin My CPP-fu wasn't up to a modification to topology_ppin(), so I added a (probably redundant) check for "dev" being a NULL pointer. Fixes: c3702a746ff5 ("topology/sysfs: Hide PPIN on systems that do not support it.") Reported-by: Stephen Rothwell <sfr@xxxxxxxxxxxxxxxx> Signed-off-by: Tony Luck <tony.luck@xxxxxxxxx> --- Better fixes with clever CPP macro tricks gratefully welcomed --- drivers/base/topology.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/base/topology.c b/drivers/base/topology.c index 706dbf8bf249..31fae51fd340 100644 --- a/drivers/base/topology.c +++ b/drivers/base/topology.c @@ -157,7 +157,7 @@ static umode_t topology_is_visible(struct kobject *kobj, { struct device *dev = kobj_to_dev(kobj); - if (attr == &dev_attr_ppin.attr && !topology_ppin(dev->id)) + if (!dev || (attr == &dev_attr_ppin.attr && !topology_ppin(dev->id))) return 0; return attr->mode; -- 2.35.1