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| author | Xiongfeng Wang <wangxiongfeng2@huawei.com> | 2021-11-29 11:02:48 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2021-12-08 11:04:42 +0300 |
| commit | c649d47801df4c89c43125c8cf0a2ffdf2e7bbc1 (patch) | |
| tree | 5dc71e3ce020db9b61a9b87f7b13889feea8fb05 /drivers/cpufreq | |
| parent | c4618188b15af986c4f43bb63271edc7d07f73aa (diff) | |
| download | linux-c649d47801df4c89c43125c8cf0a2ffdf2e7bbc1.tar.xz | |
cpufreq: Fix get_cpu_device() failure in add_cpu_dev_symlink()
commit 2c1b5a84669d2477d8fffe9136e86a2cff591729 upstream.
When I hot added a CPU, I found 'cpufreq' directory was not created
below /sys/devices/system/cpu/cpuX/.
It is because get_cpu_device() failed in add_cpu_dev_symlink().
cpufreq_add_dev() is the .add_dev callback of a CPU subsys interface.
It will be called when the CPU device registered into the system.
The call chain is as follows:
register_cpu()
->device_register()
->device_add()
->bus_probe_device()
->cpufreq_add_dev()
But only after the CPU device has been registered, we can get the
CPU device by get_cpu_device(), otherwise it will return NULL.
Since we already have the CPU device in cpufreq_add_dev(), pass
it to add_cpu_dev_symlink().
I noticed that the 'kobj' of the CPU device has been added into
the system before cpufreq_add_dev().
Fixes: 2f0ba790df51 ("cpufreq: Fix creation of symbolic links to policy directories")
Signed-off-by: Xiongfeng Wang <wangxiongfeng2@huawei.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Cc: All applicable <stable@vger.kernel.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/cpufreq')
| -rw-r--r-- | drivers/cpufreq/cpufreq.c | 9 |
1 files changed, 4 insertions, 5 deletions
diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c index 284e940084c6..fcb44352623e 100644 --- a/drivers/cpufreq/cpufreq.c +++ b/drivers/cpufreq/cpufreq.c @@ -1004,10 +1004,9 @@ static struct kobj_type ktype_cpufreq = { .release = cpufreq_sysfs_release, }; -static void add_cpu_dev_symlink(struct cpufreq_policy *policy, unsigned int cpu) +static void add_cpu_dev_symlink(struct cpufreq_policy *policy, unsigned int cpu, + struct device *dev) { - struct device *dev = get_cpu_device(cpu); - if (unlikely(!dev)) return; @@ -1391,7 +1390,7 @@ static int cpufreq_online(unsigned int cpu) if (new_policy) { for_each_cpu(j, policy->related_cpus) { per_cpu(cpufreq_cpu_data, j) = policy; - add_cpu_dev_symlink(policy, j); + add_cpu_dev_symlink(policy, j, get_cpu_device(j)); } policy->min_freq_req = kzalloc(2 * sizeof(*policy->min_freq_req), @@ -1565,7 +1564,7 @@ static int cpufreq_add_dev(struct device *dev, struct subsys_interface *sif) /* Create sysfs link on CPU registration */ policy = per_cpu(cpufreq_cpu_data, cpu); if (policy) - add_cpu_dev_symlink(policy, cpu); + add_cpu_dev_symlink(policy, cpu, dev); return 0; } |