Hey rafael, Does the V6 looks good to you ?
Thanks, Erwan, Le 13/02/2019 à 13:21, Erwan Velu a écrit : > The init code path has several exceptions where the module can decide not to > load. > As CONFIG_X86_INTEL_PSTATE is generally set to Y, the return code is not > reachable. > The initialization code is neither verbose of the reason why it did choose to > prematurely exit. > > This situation leads to a situation where its difficult for a user to > determine, > on a given platform, why the driver didn't load properly. > > This patch is about reporting to the user the reason/context of why the > driver failed to load. > That is a precious hint when debugging a platform. > > Signed-off-by: Erwan Velu <[email protected]> > --- > drivers/cpufreq/intel_pstate.c | 27 +++++++++++++++++++++------ > 1 file changed, 21 insertions(+), 6 deletions(-) > > diff --git a/drivers/cpufreq/intel_pstate.c b/drivers/cpufreq/intel_pstate.c > index dd66decf2087..e1ae309923bf 100644 > --- a/drivers/cpufreq/intel_pstate.c > +++ b/drivers/cpufreq/intel_pstate.c > @@ -2475,6 +2475,7 @@ static bool __init intel_pstate_no_acpi_pss(void) > kfree(pss); > } > > + pr_debug("ACPI _PSS not found\n"); > return true; > } > > @@ -2484,10 +2485,15 @@ static bool __init intel_pstate_no_acpi_pcch(void) > acpi_handle handle; > > status = acpi_get_handle(NULL, "\\_SB", &handle); > - if (ACPI_FAILURE(status)) > + if (ACPI_FAILURE(status)) { > + pr_debug("ACPI PCCH not found\n"); > return true; > + } > > - return !acpi_has_method(handle, "PCCH"); > + status = acpi_has_method(handle, "PCCH"); > + if (!status) > + pr_debug("ACPI PCCH not found\n"); > + return !status; > } > > static bool __init intel_pstate_has_acpi_ppc(void) > @@ -2502,6 +2508,7 @@ 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; > } > > @@ -2539,8 +2546,10 @@ 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("MSR_MISC_PWR_MGMT enabled\n"); > return true; > + } > } > > idx = acpi_match_platform_list(plat_info); > @@ -2606,22 +2615,28 @@ static int __init intel_pstate_init(void) > } > } else { > id = x86_match_cpu(intel_pstate_cpu_ids); > - if (!id) > + if (!id) { > + pr_info("CPU ID is not in the list of supported > devices\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_warn("Cannot enable driver as per 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("Platform already taking care of power management\n"); > return -ENODEV; > + } > > if (!hwp_active && hwp_only) > return -ENOTSUPP;
