[igt-dev] [PATCH i-g-t v2] tests/perf_pmu: Restore runtime PM at subtest exit

[Chris Wilson]

Quoting Tvrtko Ursulin (2018-07-20 10:42:55)
> From: Tvrtko Ursulin <tvrtko.ursulin at intel.com>
> 
> Restore runtime PM state (via a newly added library function) when the
> test which sets it up exit. This was we avoid running all subsequent sub-
> tests in the aggressive runtime PM mode.
> 
> v2:
>  * Skip double restore. (Chris Wilson)
>  * Close previously leaked fd.
> 
> Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin at intel.com>
> ---
>  lib/igt_pm.c     | 20 ++++++++++++++++++--
>  lib/igt_pm.h     |  1 +
>  tests/perf_pmu.c |  3 +++
>  3 files changed, 22 insertions(+), 2 deletions(-)
> 
> diff --git a/lib/igt_pm.c b/lib/igt_pm.c
> index 8ac132269d79..512ad9b31951 100644
> --- a/lib/igt_pm.c
> +++ b/lib/igt_pm.c
> @@ -291,16 +291,24 @@ void igt_pm_restore_sata_link_power_management(int8_t *pm_data)
>         free(file_name);
>  }
>  #define POWER_DIR "/sys/devices/pci0000:00/0000:00:02.0/power"
> -/* We just leak this on exit ... */
>  int pm_status_fd = -1;
>  
>  static char __igt_pm_runtime_autosuspend[64];
>  static char __igt_pm_runtime_control[64];
>  
> -static void __igt_pm_runtime_exit_handler(int sig)
> +/**
> + * igt_restore_runtime_pm:
> + *
> + * Restores the runtime PM configuration as it was before the call to
> + * igt_setup_runtime_pm.
> + */
> +void igt_restore_runtime_pm(void)
>  {
>         int fd;
>  
> +       if (pm_status_fd < 0)
> +               return;
> +
>         igt_debug("Restoring runtime management to '%s' and '%s'\n",
>                   __igt_pm_runtime_autosuspend,
>                   __igt_pm_runtime_control);

Hmm. Did we make our igt_debug() signal safe? The open/read/write/close
are ok.  igt_vlog() is definetly not signal-safe. Not the fault of this
patch, but I strongly advise that the debug/warn are removed from this
function and handled in the caller for !exit_handler.

Reviewed-by: Chris Wilson <chris at chris-wilson.co.uk>
-Chris