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authorXiaoguang Chen <chenxg@marvell.com>2013-11-07 10:28:50 +0800
committerRafael J. Wysocki <rafael.j.wysocki@intel.com>2013-11-07 19:36:19 +0100
commit3baa976ae644f76f5cdb5be0fb26754c3bfb32cb (patch)
tree5c571eb6bfb164a128c18050f310189275061159 /drivers/cpufreq
parentfbbcdc0744dace5fcc8147d11c5fb0791126848a (diff)
downloadlinux-3baa976ae644f76f5cdb5be0fb26754c3bfb32cb.tar.bz2
cpufreq: conservative: fix requested_freq reduction issue
When decreasing frequency, requested_freq may be less than freq_target, So requested_freq minus freq_target may be negative, But reqested_freq's unit is unsigned int, then the negative result will be one larger interger which may be even higher than requested_freq. This patch is to fix such issue. when result becomes negative, set requested_freq as the min value of policy. Signed-off-by: Xiaoguang Chen <chenxg@marvell.com> Acked-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Diffstat (limited to 'drivers/cpufreq')
-rw-r--r--drivers/cpufreq/cpufreq_conservative.c7
1 files changed, 6 insertions, 1 deletions
diff --git a/drivers/cpufreq/cpufreq_conservative.c b/drivers/cpufreq/cpufreq_conservative.c
index f62d822048e6..218460fcd2e4 100644
--- a/drivers/cpufreq/cpufreq_conservative.c
+++ b/drivers/cpufreq/cpufreq_conservative.c
@@ -80,13 +80,18 @@ static void cs_check_cpu(int cpu, unsigned int load)
/* Check for frequency decrease */
if (load < cs_tuners->down_threshold) {
+ unsigned int freq_target;
/*
* if we cannot reduce the frequency anymore, break out early
*/
if (policy->cur == policy->min)
return;
- dbs_info->requested_freq -= get_freq_target(cs_tuners, policy);
+ freq_target = get_freq_target(cs_tuners, policy);
+ if (dbs_info->requested_freq > freq_target)
+ dbs_info->requested_freq -= freq_target;
+ else
+ dbs_info->requested_freq = policy->min;
__cpufreq_driver_target(policy, dbs_info->requested_freq,
CPUFREQ_RELATION_L);