lkml.org 
[lkml]   [2020]   [Feb]   [26]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH] cpufreq: Fix policy initialization for internal governor drivers
Date
From: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

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/39fb762880c27da110086741315ca8b111d781cd.camel@gmail.com/
Reported-by: Artem Bityutskiy <dedekind1@gmail.com>
Cc: 5.4+ <stable@vger.kernel.org> # 5.4+
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
---

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
===================================================================
--- linux-pm.orig/drivers/cpufreq/cpufreq.c
+++ linux-pm/drivers/cpufreq/cpufreq.c
@@ -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.
+ */
+ if (pol == CPUFREQ_POLICY_UNKNOWN)
+ pol = policy->policy;
}
+ if (pol != CPUFREQ_POLICY_PERFORMANCE &&
+ pol != CPUFREQ_POLICY_POWERSAVE)
+ return -ENODATA;
}

return cpufreq_set_policy(policy, gov, pol);


\
 
 \ /
  Last update: 2020-02-26 22:41    [W:0.042 / U:9.204 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site