Re: [PATCH] powerpc/pseries: energy driver only print message when LPAR guest

Vaidyanathan Srinivasan [off-list ref] writes:

* Nicholas Piggin [off-list ref] [2017-07-21 11:16:44]:

quoted

diff --git a/arch/powerpc/platforms/pseries/pseries_energy.c b/arch/powerpc/platforms/pseries/pseries_energy.c
index 164a13d3998a..35c891aabef0 100644
--- a/arch/powerpc/platforms/pseries/pseries_energy.c
+++ b/arch/powerpc/platforms/pseries/pseries_energy.c

@@ -229,10 +229,9 @@ static int __init pseries_energy_init(void)
 	int cpu, err;
 	struct device *cpu_dev;

-	if (!firmware_has_feature(FW_FEATURE_BEST_ENERGY)) {
-		printk(KERN_INFO "Hypercall H_BEST_ENERGY not supported\n");
-		return 0;
-	}
+	if (!firmware_has_feature(FW_FEATURE_BEST_ENERGY))
+		return 0; /* H_BEST_ENERGY hcall not supported */
+

The first patch (!firmware_has_feature(FW_FEATURE_LPAR)) would be
ideal, but we do not have this in KVM guest case also.

Yeah we do.

It should really be called FW_FEATURE_RUNNING_UNDER_PAPR_HYPERVISOR.

static int __init probe_fw_features(unsigned long node, const char *uname, int
				    depth, void *data)
{
	....
	if (!strcmp(uname, "rtas") || !strcmp(uname, "rtas@0")) {
		prop = of_get_flat_dt_prop(node, "ibm,hypertas-functions", &len);
		if (prop) {
			powerpc_firmware_features |= FW_FEATURE_LPAR;


Qemu initialises that property unconditionally in spapr_dt_rtas().

cheers