diff options
| author | Nishanth Menon <nm@ti.com> | 2013-01-18 19:52:33 +0000 |
|---|---|---|
| committer | Rafael J. Wysocki <rafael.j.wysocki@intel.com> | 2013-01-22 13:28:39 +0100 |
| commit | 78e8eb8feab7d85f4cc215afe1457a228bf4eed9 (patch) | |
| tree | 409aa5ca48b0ee458c5a55956ca4c73dc44d2819 /drivers/cpufreq/cpufreq-cpu0.c | |
| parent | f44d188acdca1a34e4439ca6a173f85086e0e655 (diff) | |
| download | lwn-78e8eb8feab7d85f4cc215afe1457a228bf4eed9.tar.gz lwn-78e8eb8feab7d85f4cc215afe1457a228bf4eed9.zip | |
cpufreq: cpufreq-cpu0: use RCU locks around usage of OPP
OPP pointer is RCU protected, hence after finding it, de-reference
also should be protected with the same RCU context else the OPP
pointer may become invalid.
Reported-by: Jack Mitchell <jack@embed.me.uk>
Tested-by: Alexander Holler <holler@ahsoftware.de>
Tested-by: Jack Mitchell <jack@embed.me.uk>
Acked-by: Alexander Holler <holler@ahsoftware.de>
Signed-off-by: Nishanth Menon <nm@ti.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Diffstat (limited to 'drivers/cpufreq/cpufreq-cpu0.c')
| -rw-r--r-- | drivers/cpufreq/cpufreq-cpu0.c | 5 |
1 files changed, 5 insertions, 0 deletions
diff --git a/drivers/cpufreq/cpufreq-cpu0.c b/drivers/cpufreq/cpufreq-cpu0.c index 52bf36d599f5..debc5a7c8db6 100644 --- a/drivers/cpufreq/cpufreq-cpu0.c +++ b/drivers/cpufreq/cpufreq-cpu0.c @@ -71,12 +71,15 @@ static int cpu0_set_target(struct cpufreq_policy *policy, } if (cpu_reg) { + rcu_read_lock(); opp = opp_find_freq_ceil(cpu_dev, &freq_Hz); if (IS_ERR(opp)) { + rcu_read_unlock(); pr_err("failed to find OPP for %ld\n", freq_Hz); return PTR_ERR(opp); } volt = opp_get_voltage(opp); + rcu_read_unlock(); tol = volt * voltage_tolerance / 100; volt_old = regulator_get_voltage(cpu_reg); } @@ -236,12 +239,14 @@ static int cpu0_cpufreq_driver_init(void) */ for (i = 0; freq_table[i].frequency != CPUFREQ_TABLE_END; i++) ; + rcu_read_lock(); opp = opp_find_freq_exact(cpu_dev, freq_table[0].frequency * 1000, true); min_uV = opp_get_voltage(opp); opp = opp_find_freq_exact(cpu_dev, freq_table[i-1].frequency * 1000, true); max_uV = opp_get_voltage(opp); + rcu_read_unlock(); ret = regulator_set_voltage_time(cpu_reg, min_uV, max_uV); if (ret > 0) transition_latency += ret * 1000; |