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platform/x86: intel_telemetry: Fix suspend stats 

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.bhardwaj@intel.com>
Signed-off-by: Souvik Kumar Chakravarty <souvik.k.chakravarty@intel.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
hifive-unleashed-5.1
Chakravarty, Souvik K 2017-11-24 19:04:42 +05:30 committed by Andy Shevchenko
parent 9c916549c0
commit 0946a05fd2
1 changed files with 25 additions and 0 deletions
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25
drivers/platform/x86/intel_telemetry_debugfs.c
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@ -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;