recipes-kernel/linux/linux-omap-2.6.39/pm/linux-omap-2.6.39-ti-pm-wip-cpufreq-fixes/0006-OMAP2-cpufreq-fix-freq_table-leak.patch

   1 From 9303bae0e4acf8a8b3b0c682d6655a656fc776bf Mon Sep 17 00:00:00 2001
   2 From: Nishanth Menon <nm@ti.com>
   3 Date: Wed, 18 May 2011 01:48:23 -0500
   4 Subject: [PATCH 6/6] OMAP2+: cpufreq: fix freq_table leak
   5
   6 Since we have two cpus the cpuinit call for cpu1 causes
   7 freq_table of cpu0 to be overwritten. instead, we maintain
   8 a counter to keep track of cpus who use the cpufreq table
   9 allocate it once(one freq table for all CPUs) and free them
  10 once the last user is done with it.
  11
  12 Signed-off-by: Nishanth Menon <nm@ti.com>
  13 Signed-off-by: Koen Kooi <koen@dominion.thruhere.net>
  14 ---
  15  arch/arm/mach-omap2/omap2plus-cpufreq.c |   33 ++++++++++++++++++++++++------
  16  1 files changed, 26 insertions(+), 7 deletions(-)
  17
  18 diff --git a/arch/arm/mach-omap2/omap2plus-cpufreq.c b/arch/arm/mach-omap2/omap2plus-cpufreq.c
  19 index d0b4f97..fc3d0fb 100644
  20 --- a/arch/arm/mach-omap2/omap2plus-cpufreq.c
  21 +++ b/arch/arm/mach-omap2/omap2plus-cpufreq.c
  22 @@ -42,6 +42,9 @@
  23  #define VERY_HI_RATE   900000000
  24
  25  static struct cpufreq_frequency_table *freq_table;
  26 +static int freq_table_users;
  27 +static DEFINE_MUTEX(freq_table_lock);
  28 +
  29  static struct clk *mpu_clk;
  30
  31  static int omap_verify_speed(struct cpufreq_policy *policy)
  32 @@ -172,6 +175,18 @@ skip_lpj:
  33         return ret;
  34  }
  35
  36 +static void freq_table_free(void)
  37 +{
  38 +       if (!freq_table_users)
  39 +               return;
  40 +       freq_table_users--;
  41 +       if (freq_table_users)
  42 +               return;
  43 +       clk_exit_cpufreq_table(&freq_table);
  44 +       kfree(freq_table);
  45 +       freq_table = NULL;
  46 +}
  47 +
  48  static int __cpuinit omap_cpu_init(struct cpufreq_policy *policy)
  49  {
  50         int result = 0;
  51 @@ -199,14 +214,18 @@ static int __cpuinit omap_cpu_init(struct cpufreq_policy *policy)
  52                 return -EINVAL;
  53         }
  54
  55 +       mutex_lock(&freq_table_lock);
  56         /*
  57          * if we dont get cpufreq table using opp, use traditional omap2 lookup
  58          * as a fallback
  59          */
  60 -       if (opp_init_cpufreq_table(mpu_dev, &freq_table))
  61 -               clk_init_cpufreq_table(&freq_table);
  62 +       if (!freq_table) {
  63 +               if (opp_init_cpufreq_table(mpu_dev, &freq_table))
  64 +                       clk_init_cpufreq_table(&freq_table);
  65 +       }
  66
  67         if (freq_table) {
  68 +               freq_table_users++;
  69                 result = cpufreq_frequency_table_cpuinfo(policy, freq_table);
  70                 if (!result) {
  71                         cpufreq_frequency_table_get_attr(freq_table,
  72 @@ -215,10 +234,10 @@ static int __cpuinit omap_cpu_init(struct cpufreq_policy *policy)
  73                         clk_exit_cpufreq_table(&freq_table);
  74                         WARN(true, "%s: fallback to clk_round(freq_table=%d)\n",
  75                                         __func__, result);
  76 -                       kfree(freq_table);
  77 -                       freq_table = NULL;
  78 +                       freq_table_free();
  79                 }
  80         }
  81 +       mutex_unlock(&freq_table_lock);
  82
  83         if (!freq_table) {
  84                 policy->cpuinfo.min_freq = clk_round_rate(mpu_clk, 0) / 1000;
  85 @@ -251,9 +270,9 @@ static int __cpuinit omap_cpu_init(struct cpufreq_policy *policy)
  86
  87  static int omap_cpu_exit(struct cpufreq_policy *policy)
  88  {
  89 -       clk_exit_cpufreq_table(&freq_table);
  90 -       kfree(freq_table);
  91 -       freq_table = NULL;
  92 +       mutex_lock(&freq_table_lock);
  93 +       freq_table_free();
  94 +       mutex_unlock(&freq_table_lock);
  95         clk_put(mpu_clk);
  96         return 0;
  97  }
  98 --
  99 1.6.6.1
 100