| Message ID | c7bce101b2d7d107ba3c89779fe6800060e8edc4.1715356532.git.perry.yuan@amd.com (mailing list archive) |
|---|---|
| State | Needs ACK |
| Headers | show |
| Series | AMD Pstate Driver Fixes and Improvements | expand |
Hello Perry, On 5/13/2024 7:37 AM, Perry Yuan wrote: > To enhance the debugging capability of the driver loading failure for > broken CPPC ACPI tables, it can optimize the expression by moving the > verification of `min_freq`, `nominal_freq`, and other dependency values > to the `amd_pstate_init_freq()` function where they are initialized. > If any of these values are incorrect, the `amd-pstate` driver will not be registered. > > By ensuring that these values are correct before they are used, it will facilitate > the debugging process when encountering driver loading failures due to faulty CPPC > ACPI tables from BIOS > > Signed-off-by: Perry Yuan <perry.yuan@amd.com> > --- > drivers/cpufreq/amd-pstate.c | 35 ++++++++++++++++++----------------- > 1 file changed, 18 insertions(+), 17 deletions(-) > > diff --git a/drivers/cpufreq/amd-pstate.c b/drivers/cpufreq/amd-pstate.c > index 6a342b0c0140..614f6fac0764 100644 > --- a/drivers/cpufreq/amd-pstate.c > +++ b/drivers/cpufreq/amd-pstate.c > @@ -889,6 +889,24 @@ static int amd_pstate_init_freq(struct amd_cpudata *cpudata) > WRITE_ONCE(cpudata->nominal_freq, nominal_freq); > WRITE_ONCE(cpudata->max_freq, max_freq); > > + /** > + * Below values need to be initialized correctly, otherwise driver will fail to load > + * max_freq is calculated according to (nominal_freq * highest_perf)/nominal_perf > + * lowest_nonlinear_freq is a value between [min_freq, nominal_freq] > + * Check _CPC in ACPI table objects if any values are incorrect > + */ > + if (min_freq <= 0 || max_freq <= 0 || nominal_freq <= 0 || min_freq > max_freq) { > + pr_err("min_freq(%d) or max_freq(%d) or nominal_freq(%d) value is incorrect\n", > + min_freq, max_freq, nominal_freq); > + return -EINVAL; > + } > + > + if (lowest_nonlinear_freq <= min_freq || lowest_nonlinear_freq > nominal_freq * 1000) { > + pr_err("lowest_nonlinear_freq(%d) value is out of range [min_freq(%d), nominal_freq(%d)]\n", > + lowest_nonlinear_freq, min_freq, nominal_freq * 1000); A reminder, we should fix the below code section (due to only nominal freq being in MHz), 685 static int amd_pstate_set_boost(struct cpufreq_policy *policy, int state) 686 { 687 struct amd_cpudata *cpudata = policy->driver_data; 688 int ret; 689 690 if (!cpudata->boost_supported) { 691 pr_err("Boost mode is not supported by this processor or SBIOS\n"); 692 return -EINVAL; 693 } 694 695 if (state) 696 policy->cpuinfo.max_freq = cpudata->max_freq; 697 else 698 policy->cpuinfo.max_freq = cpudata->nominal_freq; <--- mismatch in left and right hand side units To avoid below situation(from a Zen4 AMD EPYC system with boost disabled), /sys/devices/system/cpu/cpu0/cpufreq# cat scaling_max_freq 2151 <--- MHz /sys/devices/system/cpu/cpu0/cpufreq# cat amd_pstate_max_freq 2287000 <--- KHz Thanks, Dhananjay > + return -EINVAL; > + } > + > return 0; > } > > @@ -927,15 +945,6 @@ static int amd_pstate_cpu_init(struct cpufreq_policy *policy) > max_freq = READ_ONCE(cpudata->max_freq); > nominal_freq = READ_ONCE(cpudata->nominal_freq); > > - if (min_freq <= 0 || max_freq <= 0 || > - nominal_freq <= 0 || min_freq > max_freq) { > - dev_err(dev, > - "min_freq(%d) or max_freq(%d) or nominal_freq (%d) value is incorrect, check _CPC in ACPI tables\n", > - min_freq, max_freq, nominal_freq); > - ret = -EINVAL; > - goto free_cpudata1; > - } > - > policy->cpuinfo.transition_latency = amd_pstate_get_transition_latency(policy->cpu); > policy->transition_delay_us = amd_pstate_get_transition_delay_us(policy->cpu); > > @@ -1388,14 +1397,6 @@ static int amd_pstate_epp_cpu_init(struct cpufreq_policy *policy) > min_freq = READ_ONCE(cpudata->min_freq); > max_freq = READ_ONCE(cpudata->max_freq); > nominal_freq = READ_ONCE(cpudata->nominal_freq); > - if (min_freq <= 0 || max_freq <= 0 || > - nominal_freq <= 0 || min_freq > max_freq) { > - dev_err(dev, > - "min_freq(%d) or max_freq(%d) or nominal_freq(%d) value is incorrect, check _CPC in ACPI tables\n", > - min_freq, max_freq, nominal_freq); > - ret = -EINVAL; > - goto free_cpudata1; > - } > > policy->cpuinfo.min_freq = min_freq; > policy->cpuinfo.max_freq = max_freq;
diff --git a/drivers/cpufreq/amd-pstate.c b/drivers/cpufreq/amd-pstate.c index 6a342b0c0140..614f6fac0764 100644 --- a/drivers/cpufreq/amd-pstate.c +++ b/drivers/cpufreq/amd-pstate.c @@ -889,6 +889,24 @@ static int amd_pstate_init_freq(struct amd_cpudata *cpudata) WRITE_ONCE(cpudata->nominal_freq, nominal_freq); WRITE_ONCE(cpudata->max_freq, max_freq); + /** + * Below values need to be initialized correctly, otherwise driver will fail to load + * max_freq is calculated according to (nominal_freq * highest_perf)/nominal_perf + * lowest_nonlinear_freq is a value between [min_freq, nominal_freq] + * Check _CPC in ACPI table objects if any values are incorrect + */ + if (min_freq <= 0 || max_freq <= 0 || nominal_freq <= 0 || min_freq > max_freq) { + pr_err("min_freq(%d) or max_freq(%d) or nominal_freq(%d) value is incorrect\n", + min_freq, max_freq, nominal_freq); + return -EINVAL; + } + + if (lowest_nonlinear_freq <= min_freq || lowest_nonlinear_freq > nominal_freq * 1000) { + pr_err("lowest_nonlinear_freq(%d) value is out of range [min_freq(%d), nominal_freq(%d)]\n", + lowest_nonlinear_freq, min_freq, nominal_freq * 1000); + return -EINVAL; + } + return 0; } @@ -927,15 +945,6 @@ static int amd_pstate_cpu_init(struct cpufreq_policy *policy) max_freq = READ_ONCE(cpudata->max_freq); nominal_freq = READ_ONCE(cpudata->nominal_freq); - if (min_freq <= 0 || max_freq <= 0 || - nominal_freq <= 0 || min_freq > max_freq) { - dev_err(dev, - "min_freq(%d) or max_freq(%d) or nominal_freq (%d) value is incorrect, check _CPC in ACPI tables\n", - min_freq, max_freq, nominal_freq); - ret = -EINVAL; - goto free_cpudata1; - } - policy->cpuinfo.transition_latency = amd_pstate_get_transition_latency(policy->cpu); policy->transition_delay_us = amd_pstate_get_transition_delay_us(policy->cpu); @@ -1388,14 +1397,6 @@ static int amd_pstate_epp_cpu_init(struct cpufreq_policy *policy) min_freq = READ_ONCE(cpudata->min_freq); max_freq = READ_ONCE(cpudata->max_freq); nominal_freq = READ_ONCE(cpudata->nominal_freq); - if (min_freq <= 0 || max_freq <= 0 || - nominal_freq <= 0 || min_freq > max_freq) { - dev_err(dev, - "min_freq(%d) or max_freq(%d) or nominal_freq(%d) value is incorrect, check _CPC in ACPI tables\n", - min_freq, max_freq, nominal_freq); - ret = -EINVAL; - goto free_cpudata1; - } policy->cpuinfo.min_freq = min_freq; policy->cpuinfo.max_freq = max_freq;
To enhance the debugging capability of the driver loading failure for broken CPPC ACPI tables, it can optimize the expression by moving the verification of `min_freq`, `nominal_freq`, and other dependency values to the `amd_pstate_init_freq()` function where they are initialized. If any of these values are incorrect, the `amd-pstate` driver will not be registered. By ensuring that these values are correct before they are used, it will facilitate the debugging process when encountering driver loading failures due to faulty CPPC ACPI tables from BIOS Signed-off-by: Perry Yuan <perry.yuan@amd.com> --- drivers/cpufreq/amd-pstate.c | 35 ++++++++++++++++++----------------- 1 file changed, 18 insertions(+), 17 deletions(-)