This reverts commit 790d849bf811a8ab5d4cd2cce0f6fda92f6aebf2. Using a v4.7-rc7 kernel on a HP ProLiant triggered following messages pcc-cpufreq: (v1.10.00) driver loaded with frequency limits: 1200 MHz, 2800 MHz cpufreq: ondemand governor failed, too long transition latency of HW, fallback to performance governor The last line was shown for each CPU in the system. Testing v4.5 (where commit 790d849b was integrated) triggered similar messages. Same behaviour on a 2nd HP Proliant system. So commit 790d849bf (cpufreq: pcc-cpufreq: update default value of cpuinfo_transition_latency) causes the system to use performance governor which, I guess, was not the intention of the patch. Enabling debug output in pcc-cpufreq provides following verbose output: pcc-cpufreq: (v1.10.00) driver loaded with frequency limits: 1200 MHz, 2800 MHz pcc_get_offset: for CPU 0: pcc_cpu_data input_offset: 0x44, pcc_cpu_data output_offset: 0x48 init: policy->max is 2800000, policy->min is 1200000 get: get_freq for CPU 0 get: SUCCESS: (virtual) output_offset for cpu 0 is 0xffffc9000d7c0048, contains a value of: 0xff06. Speed is: 168000 MHz cpufreq: ondemand governor failed, too long transition latency of HW, fallback to performance governor target: CPU 0 should go to target freq: 2800000 (virtual) input_offset is 0xffffc9000d7c0044 target: was SUCCESSFUL for cpu 0 I am asking to revert 790d849bf to re-enable usage of ondemand governor with pcc-cpufreq. CC: Jacob Tanenbaum <jtanenba@xxxxxxxxxx> CC: <stable@xxxxxxxxxxxxxxx> # 4.5+ Signed-off-by: Andreas Herrmann <aherrmann@xxxxxxxx> --- Documentation/cpu-freq/pcc-cpufreq.txt | 4 ++-- drivers/cpufreq/pcc-cpufreq.c | 2 -- 2 files changed, 2 insertions(+), 4 deletions(-) diff --git a/Documentation/cpu-freq/pcc-cpufreq.txt b/Documentation/cpu-freq/pcc-cpufreq.txt index 0a94224..9e3c3b3 100644 --- a/Documentation/cpu-freq/pcc-cpufreq.txt +++ b/Documentation/cpu-freq/pcc-cpufreq.txt @@ -159,8 +159,8 @@ to be strictly associated with a P-state. 2.2 cpuinfo_transition_latency: ------------------------------- -The cpuinfo_transition_latency field is CPUFREQ_ETERNAL. The PCC specification -does not include a field to expose this value currently. +The cpuinfo_transition_latency field is 0. The PCC specification does +not include a field to expose this value currently. 2.3 cpuinfo_cur_freq: --------------------- diff --git a/drivers/cpufreq/pcc-cpufreq.c b/drivers/cpufreq/pcc-cpufreq.c index a7ecb9a..3f0ce2a 100644 --- a/drivers/cpufreq/pcc-cpufreq.c +++ b/drivers/cpufreq/pcc-cpufreq.c @@ -555,8 +555,6 @@ static int pcc_cpufreq_cpu_init(struct cpufreq_policy *policy) policy->min = policy->cpuinfo.min_freq = ioread32(&pcch_hdr->minimum_frequency) * 1000; - policy->cpuinfo.transition_latency = CPUFREQ_ETERNAL; - pr_debug("init: policy->max is %d, policy->min is %d\n", policy->max, policy->min); out: -- 2.1.4 -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html