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authorThomas Renninger <trenn@suse.de>2009-07-24 15:25:03 +0200
committerDave Jones <davej@redhat.com>2009-09-01 12:45:14 -0400
commit4bfa042cd304aa48cf05cd0a13c2d0794a675c0e (patch)
treec2f1a8cfa8d34d7e364acde2a2391481beeee77e /drivers/cpufreq
parentecf7e4611c89aba7c7fde1183f7e9357695fbcc5 (diff)
downloadop-kernel-dev-4bfa042cd304aa48cf05cd0a13c2d0794a675c0e.zip
op-kernel-dev-4bfa042cd304aa48cf05cd0a13c2d0794a675c0e.tar.gz
[CPUFREQ] Bail out of cpufreq_add_dev if the link for a managed CPU got created
Doing: echo 0 >cpu1/online echo 1 >cpu1/online on a managed CPU will result in: Jul 22 15:15:37 linux kernel: [ 80.013864] WARNING: at fs/sysfs/dir.c:487 sysfs_add_one+0xcf/0xe6() Jul 22 15:15:37 linux kernel: [ 80.013866] Hardware name: To Be Filled By O.E.M. Jul 22 15:15:37 linux kernel: [ 80.013868] sysfs: cannot create duplicate filename '/devices/system/cpu/cpu1/cpufreq' Jul 22 15:15:37 linux kernel: [ 80.013870] Modules linked in: powernow_k8 Jul 22 15:15:37 linux kernel: [ 80.013874] Pid: 5750, comm: bash Not tainted 2.6.31-rc2 #40 Jul 22 15:15:37 linux kernel: [ 80.013876] Call Trace: Jul 22 15:15:37 linux kernel: [ 80.013879] [<ffffffff8112ebda>] ? sysfs_add_one+0xcf/0xe6 Jul 22 15:15:37 linux kernel: [ 80.013884] [<ffffffff81041926>] warn_slowpath_common+0x77/0xa4 Jul 22 15:15:37 linux kernel: [ 80.013888] [<ffffffff810419a0>] warn_slowpath_fmt+0x3c/0x3e Jul 22 15:15:37 linux kernel: [ 80.013891] [<ffffffff8112ebda>] sysfs_add_one+0xcf/0xe6 Jul 22 15:15:37 linux kernel: [ 80.013894] [<ffffffff8112f213>] create_dir+0x58/0x87 Jul 22 15:15:37 linux kernel: [ 80.013898] [<ffffffff8112f27a>] sysfs_create_dir+0x38/0x4f Jul 22 15:15:37 linux kernel: [ 80.013902] [<ffffffff811ffb8a>] kobject_add_internal+0x11f/0x1de Jul 22 15:15:37 linux kernel: [ 80.013905] [<ffffffff811ffd21>] kobject_add_varg+0x41/0x4e Jul 22 15:15:37 linux kernel: [ 80.013908] [<ffffffff811ffd7a>] kobject_init_and_add+0x4c/0x57 Jul 22 15:15:37 linux kernel: [ 80.013913] [<ffffffff810667bc>] ? mark_lock+0x22/0x228 Jul 22 15:15:37 linux kernel: [ 80.013918] [<ffffffff813e8a3b>] cpufreq_add_dev_interface+0x40/0x1e4 ... This bug slipped in by git commit: 150b06f7f223cfd0f808737a5243cceca8ea47fa When splitting up cpufreq_add_dev, the whole cpufreq_add_dev function is not left anymore, only cpufreq_add_dev_policy. This patch should reconstruct the identical functionality again as it was before the split. CC: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com> Signed-off-by: Thomas Renninger <trenn@suse.de> Signed-off-by: Dave Jones <davej@redhat.com>
Diffstat (limited to 'drivers/cpufreq')
-rw-r--r--drivers/cpufreq/cpufreq.c20
1 files changed, 17 insertions, 3 deletions
diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c
index 8456878..bbd5c21 100644
--- a/drivers/cpufreq/cpufreq.c
+++ b/drivers/cpufreq/cpufreq.c
@@ -756,7 +756,12 @@ static struct kobj_type ktype_cpufreq = {
.release = cpufreq_sysfs_release,
};
-
+/*
+ * Returns:
+ * Negative: Failure
+ * 0: Success
+ * Positive: When we have a managed CPU and the sysfs got symlinked
+ */
int cpufreq_add_dev_policy(unsigned int cpu, struct cpufreq_policy *policy,
struct sys_device *sys_dev)
{
@@ -817,7 +822,11 @@ int cpufreq_add_dev_policy(unsigned int cpu, struct cpufreq_policy *policy,
*/
if (cpufreq_driver->exit)
cpufreq_driver->exit(policy);
- return ret;
+
+ if (!ret)
+ return 1;
+ else
+ return ret;
}
}
#endif
@@ -1001,8 +1010,13 @@ static int cpufreq_add_dev(struct sys_device *sys_dev)
CPUFREQ_START, policy);
ret = cpufreq_add_dev_policy(cpu, policy, sys_dev);
- if (ret)
+ if (ret) {
+ if (ret > 0)
+ /* This is a managed cpu, symlink created,
+ exit with 0 */
+ ret = 0;
goto err_unlock_policy;
+ }
ret = cpufreq_add_dev_interface(cpu, policy, sys_dev);
if (ret)
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