Bug 71931
| Summary: | intel_pstate: cpufreq: __cpufreq_add_dev: ->get() failed | ||
|---|---|---|---|
| Product: | Power Management | Reporter: | Patrik Lundquist (patrik.lundquist) |
| Component: | cpufreq | Assignee: | cpufreq |
| Status: | CLOSED PATCH_ALREADY_AVAILABLE | ||
| Severity: | normal | CC: | dirk.brandewie, rjw, tianyu.lan |
| Priority: | P1 | ||
| Hardware: | IA-32 | ||
| OS: | Linux | ||
| Kernel Version: | 3.13.5 | Subsystem: | |
| Regression: | Yes | Bisected commit-id: | |
| Attachments: | cpufreq: Skip current frequency initialization for ->setpolicy drivers | ||
Created attachment 129151 [details]
cpufreq: Skip current frequency initialization for ->setpolicy drivers
Attached again with a changelog and stuff. Please test!
Patch tested on an Intel Xeon CPU E3-1240 V2 @ 3.40GHz (fam: 06, model: 3a, stepping: 09) which is also an Ivy Bridge. The intel_pstate driver loads fine and cpufreq_driver->get() is no longer called when cpufreq adds the CPUs. The patch has been merged into linux-pm tree. http://git.kernel.org/cgit/linux/kernel/git/rafael/linux-pm.git/commit/?id=2ed99e39cb9392312c100d9da591c20641c64d12 |
Booting 3.13.5 on a dual socket Ivy Bridge-EP resulted in this error: [ 0.194139] smpboot: CPU0: Intel(R) Xeon(R) CPU E5-2687W v2 @ 3.40GHz (fam: 06, model: 3e, stepping: 04) ... [ 0.246755] x86: Booting SMP configuration: [ 0.250935] .... node #0, CPUs: #1 #2 #3 #4 #5 #6 #7 [ 0.357648] .... node #1, CPUs: #8 #9 #10 #11 #12 #13 #14 #15 [ 0.553293] x86: Booted up 2 nodes, 16 CPUs [ 0.557666] smpboot: Total of 16 processors activated (108850.19 BogoMIPS) ... [ 5.210204] Intel P-state driver initializing. [ 5.232407] Intel pstate controlling: cpu 0 [ 5.253628] Intel pstate controlling: cpu 1 [ 5.274899] cpufreq: __cpufreq_add_dev: ->get() failed [ 5.294856] Intel pstate controlling: cpu 2 [ 5.313553] Intel pstate controlling: cpu 3 [ 5.332526] Intel pstate controlling: cpu 4 [ 5.352347] Intel pstate controlling: cpu 5 [ 5.372112] Intel pstate controlling: cpu 6 [ 5.391097] Intel pstate controlling: cpu 7 [ 5.410272] Intel pstate controlling: cpu 8 [ 5.429092] Intel pstate controlling: cpu 9 [ 5.447714] Intel pstate controlling: cpu 10 [ 5.465872] Intel pstate controlling: cpu 11 [ 5.482942] Intel pstate controlling: cpu 12 [ 5.498414] Intel pstate controlling: cpu 13 [ 5.513586] Intel pstate controlling: cpu 14 [ 5.529200] Intel pstate controlling: cpu 15 CPU 1 is alive and well but missing the cpufreq driver. The system is running fine otherwise. Looking closer at the problem gives that intel_pstate_init_cpu() is successful but intel_pstate_get(), which is called right after by cpufreq, fails. Since all_cpu_data[1] is initialized it gives that sample->freq must be zero. So the bug should be in intel_pstate_calc_busy() which calculates sample->freq to zero. core_pct is likely 0 due to truncation in intel_pstate.c:intel_pstate_calc_busy(): core_pct = div64_u64(int_tofp(sample->aperf * 100), sample->mperf);