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authorAndreas Herrmann <andreas.herrmann3@amd.com>2012-10-23 00:55:10 +0200
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2012-10-31 10:10:22 -0700
commitb1a9fec89349d9c41ff1ab519d4bfe2bb16814b8 (patch)
tree75fd0dc02b3199215981d3895094efa7ff28ab2b
parentceb80aec3793b4e34b84849c2823d052c91a855b (diff)
downloadlinux-linaro-stable-b1a9fec89349d9c41ff1ab519d4bfe2bb16814b8.tar.gz
cpufreq / powernow-k8: Remove usage of smp_processor_id() in preemptible code
commit e4df1cbcc1f329e53a1fff7450b2229e0addff20 upstream. Commit 6889125b8b4e09c5e53e6ecab3433bed1ce198c9 (cpufreq/powernow-k8: workqueue user shouldn't migrate the kworker to another CPU) causes powernow-k8 to trigger a preempt warning, e.g.: BUG: using smp_processor_id() in preemptible [00000000] code: cpufreq/3776 caller is powernowk8_target+0x20/0x49 Pid: 3776, comm: cpufreq Not tainted 3.6.0 #9 Call Trace: [<ffffffff8125b447>] debug_smp_processor_id+0xc7/0xe0 [<ffffffff814877e7>] powernowk8_target+0x20/0x49 [<ffffffff81482b02>] __cpufreq_driver_target+0x82/0x8a [<ffffffff81484fc6>] cpufreq_governor_performance+0x4e/0x54 [<ffffffff81482c50>] __cpufreq_governor+0x8c/0xc9 [<ffffffff81482e6f>] __cpufreq_set_policy+0x1a9/0x21e [<ffffffff814839af>] store_scaling_governor+0x16f/0x19b [<ffffffff81484f16>] ? cpufreq_update_policy+0x124/0x124 [<ffffffff8162b4a5>] ? _raw_spin_unlock_irqrestore+0x2c/0x49 [<ffffffff81483640>] store+0x60/0x88 [<ffffffff811708c0>] sysfs_write_file+0xf4/0x130 [<ffffffff8111243b>] vfs_write+0xb5/0x151 [<ffffffff811126e0>] sys_write+0x4a/0x71 [<ffffffff816319a9>] system_call_fastpath+0x16/0x1b Fix this by by always using work_on_cpu(). Signed-off-by: Andreas Herrmann <andreas.herrmann3@amd.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-rw-r--r--drivers/cpufreq/powernow-k8.c9
1 files changed, 1 insertions, 8 deletions
diff --git a/drivers/cpufreq/powernow-k8.c b/drivers/cpufreq/powernow-k8.c
index 1a40935c85fd..c671369a05bf 100644
--- a/drivers/cpufreq/powernow-k8.c
+++ b/drivers/cpufreq/powernow-k8.c
@@ -1223,14 +1223,7 @@ static int powernowk8_target(struct cpufreq_policy *pol,
struct powernowk8_target_arg pta = { .pol = pol, .targfreq = targfreq,
.relation = relation };
- /*
- * Must run on @pol->cpu. cpufreq core is responsible for ensuring
- * that we're bound to the current CPU and pol->cpu stays online.
- */
- if (smp_processor_id() == pol->cpu)
- return powernowk8_target_fn(&pta);
- else
- return work_on_cpu(pol->cpu, powernowk8_target_fn, &pta);
+ return work_on_cpu(pol->cpu, powernowk8_target_fn, &pta);
}
/* Driver entry point to verify the policy and range of frequencies */