[igt-dev] [PATCH i-g-t v2] lib/igt_pm: Restore runtime pm state on test exit

Imre Deak imre.deak at intel.com
Fri Mar 2 09:29:50 UTC 2018


On Wed, Feb 28, 2018 at 03:35:06PM +0000, Tvrtko Ursulin wrote:
> From: Tvrtko Ursulin <tvrtko.ursulin at intel.com>
> 
> Some tests (the ones which call igt_setup_runtime_pm and
> igt_pm_enable_audio_runtime_pm) change default system configuration and
> never restore it.
> 
> The configured runtime suspend is aggressive and may influence behaviour
> of subsequent tests, so it is better to restore to previous values on test
> exit.
> 
> This way system behaviour, with regards to a random sequence of executed
> tests, will be more consistent from one run to another.
> 
> v2: Read failure means no runtime pm support so don't assert on it.
> 
> Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin at intel.com>
> Cc: Imre Deak <imre.deak at intel.com>
> Reviewed-by: Chris Wilson <chris at chris-wilson.co.uk> # v1

Agreed about having a consistent expected state for each test, not sure
why we didn't restore these settings :/ Btw, I feel somewhat the same
about test results being affected by previous tests, but not sure if
anything should/can be done about that.

Acked-by: Imre Deak <imre.deak at intel.com>

Some nits below.

> ---
>  lib/igt_pm.c | 122 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++---
>  1 file changed, 117 insertions(+), 5 deletions(-)
> 
> diff --git a/lib/igt_pm.c b/lib/igt_pm.c
> index 5bf5b2e23cdc..04e2b89cca95 100644
> --- a/lib/igt_pm.c
> +++ b/lib/igt_pm.c
> @@ -63,6 +63,46 @@ enum {
>  /* Remember to fix this if adding longer strings */
>  #define MAX_POLICY_STRLEN	strlen(MAX_PERFORMANCE_STR)
>  
> +static char __igt_pm_audio_runtime_power_save[64];
> +static char __igt_pm_audio_runtime_control[64];
> +
> +static void __igt_pm_audio_runtime_exit_handler(int sig)
> +{
> +	int fd;
> +
> +	igt_debug("Restoring audio power management to '%s' and '%s'\n",
> +		  __igt_pm_audio_runtime_power_save,
> +		  __igt_pm_audio_runtime_control);
> +
> +	fd = open("/sys/module/snd_hda_intel/parameters/power_save", O_WRONLY);
> +	if (fd < 0)
> +		return;
> +	if (write(fd, __igt_pm_audio_runtime_power_save,
> +		  strlen(__igt_pm_audio_runtime_power_save)) !=
> +	    strlen(__igt_pm_audio_runtime_power_save))
> +		igt_warn("Failed to restore audio power_save to '%s'\n",
> +			 __igt_pm_audio_runtime_power_save);
> +	close(fd);
> +
> +	fd = open("/sys/bus/pci/devices/0000:00:03.0/power/control", O_WRONLY);
> +	if (fd < 0)
> +		return;
> +	if (write(fd, __igt_pm_audio_runtime_control,
> +		  strlen(__igt_pm_audio_runtime_control)) !=
> +	    strlen(__igt_pm_audio_runtime_control))
> +		igt_warn("Failed to restore audio control to '%s'\n",
> +			 __igt_pm_audio_runtime_control);
> +	close(fd);
> +}
> +
> +static void strchomp(char *str)
> +{
> +	int len = strlen(str);
> +
> +	if (len && str[len - 1] == '\n')
> +		str[len - 1] = 0;
> +}
> +
>  /**
>   * igt_pm_enable_audio_runtime_pm:
>   *
> @@ -78,16 +118,32 @@ void igt_pm_enable_audio_runtime_pm(void)
>  {
>  	int fd;
>  
> -	fd = open("/sys/module/snd_hda_intel/parameters/power_save", O_WRONLY);
> +	/* Check if already enabled. */
> +	if (__igt_pm_audio_runtime_power_save[0])
> +		return;
> +
> +	fd = open("/sys/module/snd_hda_intel/parameters/power_save", O_RDWR);
>  	if (fd >= 0) {
> +		igt_assert(read(fd, __igt_pm_audio_runtime_power_save,
> +				sizeof(__igt_pm_audio_runtime_power_save)) > 0);
> +		strchomp(__igt_pm_audio_runtime_power_save);
>  		igt_assert_eq(write(fd, "1\n", 2), 2);
> +		igt_install_exit_handler(__igt_pm_audio_runtime_exit_handler);

Read/install_handler/write would avoid a potential race with ^C. There's also
link_power_management_policy which is only restored during normal exit.

>  		close(fd);
>  	}
> -	fd = open("/sys/bus/pci/devices/0000:00:03.0/power/control", O_WRONLY);
> +	fd = open("/sys/bus/pci/devices/0000:00:03.0/power/control", O_RDWR);
>  	if (fd >= 0) {
> +		igt_assert(read(fd, __igt_pm_audio_runtime_control,
> +				sizeof(__igt_pm_audio_runtime_control)) > 0);
> +		strchomp(__igt_pm_audio_runtime_control);
>  		igt_assert_eq(write(fd, "auto\n", 5), 5);
>  		close(fd);
>  	}
> +
> +	igt_debug("Saved audio power management as '%s' and '%s'\n",
> +		  __igt_pm_audio_runtime_power_save,
> +		  __igt_pm_audio_runtime_control);
> +
>  	/* Give some time for it to react. */
>  	sleep(1);
>  }
> @@ -238,6 +294,38 @@ void igt_pm_restore_sata_link_power_management(int8_t *pm_data)
>  /* 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)
> +{
> +	int fd;
> +
> +	igt_debug("Restoring runtime management to '%s' and '%s'\n",
> +		  __igt_pm_runtime_autosuspend,
> +		  __igt_pm_runtime_control);
> +
> +	fd = open(POWER_DIR "/autosuspend_delay_ms", O_WRONLY);
> +	if (fd < 0)
> +		return;
> +	if (write(fd, __igt_pm_runtime_autosuspend,
> +		  strlen(__igt_pm_runtime_autosuspend)) !=
> +	    strlen(__igt_pm_runtime_autosuspend))
> +		igt_warn("Failed to restore runtime pm autosuspend delay to '%s'\n",
> +			 __igt_pm_runtime_autosuspend);
> +	close(fd);
> +
> +	fd = open(POWER_DIR "/control", O_WRONLY);
> +	if (fd < 0)
> +		return;
> +	if (write(fd, __igt_pm_runtime_control,
> +		  strlen(__igt_pm_runtime_control)) !=
> +	    strlen(__igt_pm_runtime_control))
> +		igt_warn("Failed to restore runtime pm control to '%s'\n",
> +			 __igt_pm_runtime_control);
> +	close(fd);
> +}
> +
>  /**
>   * igt_setup_runtime_pm:
>   *
> @@ -261,12 +349,26 @@ bool igt_setup_runtime_pm(void)
>  	/* Our implementation uses autosuspend. Try to set it to 0ms so the test
>  	 * suite goes faster and we have a higher probability of triggering race
>  	 * conditions. */
> -	fd = open(POWER_DIR "/autosuspend_delay_ms", O_WRONLY);
> +	fd = open(POWER_DIR "/autosuspend_delay_ms", O_RDWR);
>  	igt_assert_f(fd >= 0,
>  		     "Can't open " POWER_DIR "/autosuspend_delay_ms\n");
>  
> -	/* If we fail to write to the file, it means this system doesn't support
> -	 * runtime PM. */
> +	/*
> +	 * Save previous values to be able to  install exit handler to restore
> +	 * them on test exit.
> +	 */
> +	size = read(fd, __igt_pm_runtime_autosuspend,
> +		    sizeof(__igt_pm_runtime_autosuspend));
> +
> +	/*
> +	 * If we fail to read from the file, it means this system doesn't
> +	 * support runtime PM.
> +	 */
> +	if (size <= 0) {
> +		close(fd);
> +		return false;
> +	}
> +
>  	size = write(fd, "0\n", 2);
>  
>  	close(fd);
> @@ -274,10 +376,20 @@ bool igt_setup_runtime_pm(void)
>  	if (size != 2)
>  		return false;
>  
> +	strchomp(__igt_pm_runtime_autosuspend);
> +	igt_install_exit_handler(__igt_pm_runtime_exit_handler);
> +
>  	/* We know we support runtime PM, let's try to enable it now. */
>  	fd = open(POWER_DIR "/control", O_RDWR);
>  	igt_assert_f(fd >= 0, "Can't open " POWER_DIR "/control\n");
>  
> +	igt_assert(read(fd, __igt_pm_runtime_control,
> +			sizeof(__igt_pm_runtime_control)) > 0);
> +	strchomp(__igt_pm_runtime_control);
> +
> +	igt_debug("Saved runtime power management as '%s' and '%s'\n",
> +		  __igt_pm_runtime_autosuspend, __igt_pm_runtime_control);
> +
>  	size = write(fd, "auto\n", 5);
>  	igt_assert(size == 5);
>  
> -- 
> 2.14.1
> 


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