power: do not skip saving original P-state governor

[ upstream commit 190f387 ]

Currently, when we set the pstate governor to "performance", we check if
it is already set to this value, and if it is, we skip setting it.

However, we never save this value anywhere, so that next time we come
back and request the governor to be set to its original value, the
original value is empty.

Fix it by saving the original pstate governor first. While we're at it,
replace `strlcpy` with `rte_strscpy`.

Fixes: e6c6dc0 ("power: add p-state driver compatibility")

Signed-off-by: Anatoly Burakov <anatoly.burakov@intel.com>
Acked-by: Reshma Pattan <reshma.pattan@intel.com>

lib/librte_power/power_pstate_cpufreq.c

@@ -350,6 +350,9 @@ power_set_governor_performance(struct pstate_power_info *pi)
 	/* Strip off terminating '\n' */
 	strtok(buf, "\n");
 
+	/* Save the original governor */
+	rte_strscpy(pi->governor_ori, buf, sizeof(pi->governor_ori));
+
 	/* Check if current governor is performance */
 	if (strncmp(buf, POWER_GOVERNOR_PERF,
 			sizeof(POWER_GOVERNOR_PERF)) == 0) {
@@ -358,8 +361,6 @@ power_set_governor_performance(struct pstate_power_info *pi)
 				"already performance\n", pi->lcore_id);
 		goto out;
 	}
-	/* Save the original governor */
-	strlcpy(pi->governor_ori, buf, sizeof(pi->governor_ori));
 
 	/* Write 'performance' to the governor */
 	val = fseek(f, 0, SEEK_SET);