diff --git a/drivers/cpufreq/intel_pstate.c b/drivers/cpufreq/intel_pstate.c index 5ab6a4fe93aa..75a5408e6981 100644 --- a/drivers/cpufreq/intel_pstate.c +++ b/drivers/cpufreq/intel_pstate.c @@ -2476,6 +2476,7 @@ static bool __init intel_pstate_no_acpi_pss(void) kfree(pss); } + pr_debug("ACPI _PSS not found\n"); return true; } @@ -2486,9 +2487,14 @@ static bool __init intel_pstate_no_acpi_pcch(void) status = acpi_get_handle(NULL, "\\_SB", &handle); if (ACPI_FAILURE(status)) - return true; + goto not_found; - return !acpi_has_method(handle, "PCCH"); + if (acpi_has_method(handle, "PCCH")) + return false; + +not_found: + pr_debug("ACPI PCCH not found\n"); + return true; } static bool __init intel_pstate_has_acpi_ppc(void) @@ -2503,6 +2509,7 @@ static bool __init intel_pstate_has_acpi_ppc(void) if (acpi_has_method(pr->handle, "_PPC")) return true; } + pr_debug("ACPI _PPC not found\n"); return false; } @@ -2540,8 +2547,10 @@ static bool __init intel_pstate_platform_pwr_mgmt_exists(void) id = x86_match_cpu(intel_pstate_cpu_oob_ids); if (id) { rdmsrl(MSR_MISC_PWR_MGMT, misc_pwr); - if ( misc_pwr & (1 << 8)) + if (misc_pwr & (1 << 8)) { + pr_debug("Bit 8 in the MISC_PWR_MGMT MSR set\n"); return true; + } } idx = acpi_match_platform_list(plat_info); @@ -2607,22 +2616,28 @@ static int __init intel_pstate_init(void) } } else { id = x86_match_cpu(intel_pstate_cpu_ids); - if (!id) + if (!id) { + pr_info("CPU ID not supported\n"); return -ENODEV; + } copy_cpu_funcs((struct pstate_funcs *)id->driver_data); } - if (intel_pstate_msrs_not_valid()) + if (intel_pstate_msrs_not_valid()) { + pr_info("Invalid MSRs\n"); return -ENODEV; + } hwp_cpu_matched: /* * The Intel pstate driver will be ignored if the platform * firmware has its own power management modes. */ - if (intel_pstate_platform_pwr_mgmt_exists()) + if (intel_pstate_platform_pwr_mgmt_exists()) { + pr_info("P-states controlled by the platform\n"); return -ENODEV; + } if (!hwp_active && hwp_only) return -ENOTSUPP;