Skip to content

Commit

Permalink
cpufreq: conservative: fix requested_freq reduction issue
Browse files Browse the repository at this point in the history
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>
  • Loading branch information
Xiaoguang Chen authored and Rafael J. Wysocki committed Nov 7, 2013
1 parent fbbcdc0 commit 3baa976
Showing 1 changed file with 6 additions and 1 deletion.
7 changes: 6 additions & 1 deletion drivers/cpufreq/cpufreq_conservative.c
Original file line number Diff line number Diff line change
Expand Up @@ -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);
Expand Down

0 comments on commit 3baa976

Please sign in to comment.