Re: [PATCH v2 2/4] platform/x86: intel_telemetry: Fix suspend stats

From: Andy Shevchenko
Date: Thu Nov 23 2017 - 16:25:34 EST


On Tue, Nov 21, 2017 at 4:36 PM, Souvik Kumar Chakravarty
<souvik.k.chakravarty@xxxxxxxxx> wrote:
> 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
>
> We also remove unnecessary 'static' qualifiers from local variables.
>
> Reported-and-tested-by: Rajneesh Bhardwaj <rajneesh.bhardwaj@xxxxxxxxx>
> Signed-off-by: Souvik Kumar Chakravarty <souvik.k.chakravarty@xxxxxxxxx>

> - static u32 suspend_shlw_ctr_exit, suspend_deep_ctr_exit;
> - static u64 suspend_shlw_res_exit, suspend_deep_res_exit;
> struct telemetry_debugfs_conf *conf = debugfs_conf;
> + u32 suspend_shlw_ctr_exit, suspend_deep_ctr_exit;
> + u64 suspend_shlw_res_exit, suspend_deep_res_exit;
> int ret, index;

> + if (suspend_shlw_ctr_exit == suspend_shlw_ctr_temp &&
> + suspend_deep_ctr_exit == suspend_deep_ctr_temp) {

kbuildbot is absolutely right. How this code is supposed to work? It's flaky.

Please, redesign this approach.

--
With Best Regards,
Andy Shevchenko