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author | Chen Yu <yu.c.chen@intel.com> | 2020-10-09 11:30:38 +0800 |
---|---|---|
committer | Rafael J. Wysocki <rafael.j.wysocki@intel.com> | 2020-10-16 16:33:12 +0200 |
commit | cdc1719cd885ef490e30c14c01a6e7fee42bf2e2 (patch) | |
tree | 01da2793f91651dd686dbceab76cf1924c91d9c7 /drivers/cpufreq/intel_pstate.c | |
parent | 97148d0ae5303bcc18fcd1c9b968a9485292f32a (diff) | |
download | linux-cdc1719cd885ef490e30c14c01a6e7fee42bf2e2.tar.bz2 |
cpufreq: intel_pstate: Delete intel_pstate sysfs if failed to register the driver
There is a corner case that if the intel_pstate driver fails to be
registered (might be due to invalid MSR access) and acpi_cpufreq
takse over, the intel_pstate sysfs interface is still populated
which may confuse user space (turbostat for example):
grep . /sys/devices/system/cpu/cpu0/cpufreq/scaling_driver
acpi-cpufreq
grep . /sys/devices/system/cpu/intel_pstate/*
/sys/devices/system/cpu/intel_pstate/max_perf_pct:0
/sys/devices/system/cpu/intel_pstate/min_perf_pct:0
grep: /sys/devices/system/cpu/intel_pstate/no_turbo: Resource temporarily unavailable
grep: /sys/devices/system/cpu/intel_pstate/num_pstates: Resource temporarily unavailable
/sys/devices/system/cpu/intel_pstate/status:off
grep: /sys/devices/system/cpu/intel_pstate/turbo_pct: Resource temporarily unavailable
The mere presence of the intel_pstate sysfs interface does not mean
that intel_pstate is in use (for example, echo "off" to "status"),
but it should not be created in the failing case.
Fix this issue by deleting the intel_pstate sysfs if the driver
registration fails.
Reported-by: Wendy Wang <wendy.wang@intel.com>
Suggested-by: Zhang Rui <rui.zhang@intel.com>
Signed-off-by: Chen Yu <yu.c.chen@intel.com>
Acked-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com
[ rjw: Refactor code to avoid jumps, change function name, changelog edits ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Diffstat (limited to 'drivers/cpufreq/intel_pstate.c')
-rw-r--r-- | drivers/cpufreq/intel_pstate.c | 22 |
1 files changed, 21 insertions, 1 deletions
diff --git a/drivers/cpufreq/intel_pstate.c b/drivers/cpufreq/intel_pstate.c index 9a515c460a00..3c1455518738 100644 --- a/drivers/cpufreq/intel_pstate.c +++ b/drivers/cpufreq/intel_pstate.c @@ -1420,6 +1420,24 @@ static void __init intel_pstate_sysfs_expose_params(void) } } +static void __init intel_pstate_sysfs_remove(void) +{ + if (!intel_pstate_kobject) + return; + + sysfs_remove_group(intel_pstate_kobject, &intel_pstate_attr_group); + + if (!per_cpu_limits) { + sysfs_remove_file(intel_pstate_kobject, &max_perf_pct.attr); + sysfs_remove_file(intel_pstate_kobject, &min_perf_pct.attr); + + if (x86_match_cpu(intel_pstate_cpu_ee_disable_ids)) + sysfs_remove_file(intel_pstate_kobject, &energy_efficiency.attr); + } + + kobject_put(intel_pstate_kobject); +} + static void intel_pstate_sysfs_expose_hwp_dynamic_boost(void) { int rc; @@ -3063,8 +3081,10 @@ hwp_cpu_matched: mutex_lock(&intel_pstate_driver_lock); rc = intel_pstate_register_driver(default_driver); mutex_unlock(&intel_pstate_driver_lock); - if (rc) + if (rc) { + intel_pstate_sysfs_remove(); return rc; + } if (hwp_active) { const struct x86_cpu_id *id; |