cpufreq: Fix policy initialization for internal governor drivers

From: Rafael J. Wysocki <[email protected]>

Before commit 1e4f63aecb53 ("cpufreq: Avoid creating excessively large stack frames") the initial value of the policy field in struct cpufreq_policy set by the driver's ->init() callback was implicitly passed from cpufreq_init_policy() to cpufreq_set_policy() if the default governor was neither "performance" nor "powersave". After that commit, however, cpufreq_init_policy() must take that case into consideration explicitly and handle it as appropriate, so make that happen.

Fixes 1e4f63aecb53 ("cpufreq: Avoid creating excessively large stack frames")

Link https://lore.kernel.org/linux-pm/[email protected]/ open here

Reported-by Artem Bityutskiy <[email protected]>

Cc 5.4+ <[email protected]> # 5.4+

Signed-off-by Rafael J. Wysocki <[email protected]>

---

Note that I'm going to fast-track this patch for 5.6-rc4 which means that it will go into my linux-next branch as soon as it shows up in the lists.

Thanks and sorry for the breakage!

---
 drivers/cpufreq/cpufreq.c |   14 ++++++++++++--
 1 file changed, 12 insertions(+), 2 deletions(-)

Index: linux-pm/drivers/cpufreq/cpufreq.c
===================================================================

drivers/cpufreq/cpufreq.c +4 -2

@@ -1076,9 +1076,17 @@ static int cpufreq_init_policy(struct cp
 			pol = policy->last_policy;
 		} else if (def_gov) {
 			pol = cpufreq_parse_policy(def_gov->name);
-		} else {
-			return -ENODATA;
+			/*
+			 * In case the default governor is neiter "performance"
+			 * nor "powersave", fall back to the initial policy
+			 * value set by the driver.

From: Rafael J. Wysocki <[email protected]>

Before commit 1e4f63aecb53 ("cpufreq: Avoid creating excessively large stack frames") the initial value of the policy field in struct cpufreq_policy set by the driver's ->init() callback was implicitly passed from cpufreq_init_policy() to cpufreq_set_policy() if the default governor was neither "performance" nor "powersave". After that commit, however, cpufreq_init_policy() must take that case into consideration explicitly and handle it as appropriate, so make that happen.

Fixes 1e4f63aecb53 ("cpufreq: Avoid creating excessively large stack frames")

Link https://lore.kernel.org/linux-pm/[email protected]/ open here

Reported-by Artem Bityutskiy <[email protected]>

Cc 5.4+ <[email protected]> # 5.4+

Signed-off-by Rafael J. Wysocki <[email protected]>