@@ -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(-)