Suspend stats are not reported consistently due to a limitation in the PMC firmware. This limitation causes a delay in updating the s0ix counters and residencies in the telemetry log upon s0ix exit. As a consequence, reading these counters from the suspend-exit notifier may result in zero read.
This patch fixes this issue by cross-verifying the s0ix residencies from the GCR TELEM registers in case the counters are not incremented in the telemetry log after suspend. This fixes https://bugzilla.kernel.org/show_bug.cgi?id=197833 Reported-and-tested-by: Rajneesh Bhardwaj <rajneesh.bhard...@intel.com> Signed-off-by: Souvik Kumar Chakravarty <souvik.k.chakrava...@intel.com> --- drivers/platform/x86/intel_telemetry_debugfs.c | 25 +++++++++++++++++++++++++ 1 file changed, 25 insertions(+) Changes since v2: * Use pmc_ipc_gcr_read64() API to read 64-bits at a time * Re-introduce the static qualifier to handle the case where the telemetry suspend/resume log does not contain the s0ix residencies. In that case, we would like to retain the values from the previous/initial cycle. Changes since v1: * Use pmc_ipc_gcr_readq API to read 64-bits at a time diff --git a/drivers/platform/x86/intel_telemetry_debugfs.c b/drivers/platform/x86/intel_telemetry_debugfs.c index 4249e826..5bc4f20 100644 --- a/drivers/platform/x86/intel_telemetry_debugfs.c +++ b/drivers/platform/x86/intel_telemetry_debugfs.c @@ -890,6 +890,31 @@ static int pm_suspend_exit_cb(void) goto out; } + /* + * Due to some design limitations in the firmware, sometimes the + * counters do not get updated by the time we reach here. As a + * workaround, we try to see if this was a genuine case of sleep + * failure or not by cross-checking from PMC GCR registers directly. + */ + if (suspend_shlw_ctr_exit == suspend_shlw_ctr_temp && + suspend_deep_ctr_exit == suspend_deep_ctr_temp) { + ret = intel_pmc_gcr_read64(PMC_GCR_TELEM_SHLW_S0IX_REG, + &suspend_shlw_res_exit); + if (ret < 0) + goto out; + + ret = intel_pmc_gcr_read64(PMC_GCR_TELEM_DEEP_S0IX_REG, + &suspend_deep_res_exit); + if (ret < 0) + goto out; + + if (suspend_shlw_res_exit > suspend_shlw_res_temp) + suspend_shlw_ctr_exit++; + + if (suspend_deep_res_exit > suspend_deep_res_temp) + suspend_deep_ctr_exit++; + } + suspend_shlw_ctr_exit -= suspend_shlw_ctr_temp; suspend_deep_ctr_exit -= suspend_deep_ctr_temp; suspend_shlw_res_exit -= suspend_shlw_res_temp; -- 2.7.4
