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authorRafael J. Wysocki <rafael.j.wysocki@intel.com>2014-09-27 21:56:08 +0200
committerRafael J. Wysocki <rafael.j.wysocki@intel.com>2014-09-29 15:35:50 +0200
commite65b5ddba84634f31d42dfd86013f4c6be5e9e32 (patch)
treeab5c85b126a9e4af838947371e5b42f5fc83aa80
parentfe82dcec644244676d55a1384c958d5f67979adb (diff)
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cpufreq: pcc-cpufreq: Fix wait_event() under spinlock
Fix the following bug introduced by commit 8fec051eea73 (cpufreq: Convert existing drivers to use cpufreq_freq_transition_{begin|end}) that forgot to move the spin_lock() in pcc_cpufreq_target() past cpufreq_freq_transition_begin() which calls wait_event(): BUG: sleeping function called from invalid context at drivers/cpufreq/cpufreq.c:370 in_atomic(): 1, irqs_disabled(): 0, pid: 2636, name: modprobe Preemption disabled at:[<ffffffffa04d74d7>] pcc_cpufreq_target+0x27/0x200 [pcc_cpufreq] [ 51.025044] CPU: 57 PID: 2636 Comm: modprobe Tainted: G E 3.17.0-default #7 Hardware name: Hewlett-Packard ProLiant DL980 G7, BIOS P66 07/07/2010 00000000ffffffff ffff88026c46b828 ffffffff81589dbd 0000000000000000 ffff880037978090 ffff88026c46b848 ffffffff8108e1df ffff880037978090 0000000000000000 ffff88026c46b878 ffffffff8108e298 ffff88026d73ec00 Call Trace: [<ffffffff81589dbd>] dump_stack+0x4d/0x90 [<ffffffff8108e1df>] ___might_sleep+0x10f/0x180 [<ffffffff8108e298>] __might_sleep+0x48/0xd0 [<ffffffff8145b905>] cpufreq_freq_transition_begin+0x75/0x140 drivers/cpufreq/cpufreq.c:370 wait_event(policy->transition_wait, !policy->transition_ongoing); [<ffffffff8108fc99>] ? preempt_count_add+0xb9/0xc0 [<ffffffffa04d7513>] pcc_cpufreq_target+0x63/0x200 [pcc_cpufreq] drivers/cpufreq/pcc-cpufreq.c:207 spin_lock(&pcc_lock); [<ffffffff810e0d0f>] ? update_ts_time_stats+0x7f/0xb0 [<ffffffff8145be55>] __cpufreq_driver_target+0x85/0x170 [<ffffffff8145e4c8>] od_check_cpu+0xa8/0xb0 [<ffffffff8145ef10>] dbs_check_cpu+0x180/0x1d0 [<ffffffff8145f310>] cpufreq_governor_dbs+0x3b0/0x720 [<ffffffff8145ebe3>] od_cpufreq_governor_dbs+0x33/0xe0 [<ffffffff814593d9>] __cpufreq_governor+0xa9/0x210 [<ffffffff81459fb2>] cpufreq_set_policy+0x1e2/0x2e0 [<ffffffff8145a6cc>] cpufreq_init_policy+0x8c/0x110 [<ffffffff8145c9a0>] ? cpufreq_update_policy+0x1b0/0x1b0 [<ffffffff8108fb99>] ? preempt_count_sub+0xb9/0x100 [<ffffffff8145c6c6>] __cpufreq_add_dev+0x596/0x6b0 [<ffffffffa016c608>] ? pcc_cpufreq_probe+0x4b4/0x4b4 [pcc_cpufreq] [<ffffffff8145c7ee>] cpufreq_add_dev+0xe/0x10 [<ffffffff81408e81>] subsys_interface_register+0xc1/0xf0 [<ffffffff8108fb99>] ? preempt_count_sub+0xb9/0x100 [<ffffffff8145b3d7>] cpufreq_register_driver+0x117/0x2a0 [<ffffffffa016c65d>] pcc_cpufreq_init+0x55/0x9f8 [pcc_cpufreq] [<ffffffffa016c608>] ? pcc_cpufreq_probe+0x4b4/0x4b4 [pcc_cpufreq] [<ffffffff81000298>] do_one_initcall+0xc8/0x1f0 [<ffffffff811a731d>] ? __vunmap+0x9d/0x100 [<ffffffff810eb9a0>] do_init_module+0x30/0x1b0 [<ffffffff810edfa6>] load_module+0x686/0x710 [<ffffffff810ebb20>] ? do_init_module+0x1b0/0x1b0 [<ffffffff810ee1db>] SyS_init_module+0x9b/0xc0 [<ffffffff8158f7a9>] system_call_fastpath+0x16/0x1b Fixes: 8fec051eea73 (cpufreq: Convert existing drivers to use cpufreq_freq_transition_{begin|end}) Reported-and-tested-by: Mike Galbraith <umgwanakikbuti@gmail.com> Cc: 3.15+ <stable@vger.kernel.org> # 3.15+ Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
-rw-r--r--drivers/cpufreq/pcc-cpufreq.c2
1 files changed, 1 insertions, 1 deletions
diff --git a/drivers/cpufreq/pcc-cpufreq.c b/drivers/cpufreq/pcc-cpufreq.c
index 728a2d879499..4d2c8e861089 100644
--- a/drivers/cpufreq/pcc-cpufreq.c
+++ b/drivers/cpufreq/pcc-cpufreq.c
@@ -204,7 +204,6 @@ static int pcc_cpufreq_target(struct cpufreq_policy *policy,
u32 input_buffer;
int cpu;
- spin_lock(&pcc_lock);
cpu = policy->cpu;
pcc_cpu_data = per_cpu_ptr(pcc_cpu_info, cpu);
@@ -216,6 +215,7 @@ static int pcc_cpufreq_target(struct cpufreq_policy *policy,
freqs.old = policy->cur;
freqs.new = target_freq;
cpufreq_freq_transition_begin(policy, &freqs);
+ spin_lock(&pcc_lock);
input_buffer = 0x1 | (((target_freq * 100)
/ (ioread32(&pcch_hdr->nominal) * 1000)) << 8);