[Intel-gfx] [PATCH i-g-t] lib/igt_pm: Lib for power management

Thomas Wood thomas.wood at intel.com
Fri Dec 18 11:27:01 PST 2015


On 15 December 2015 at 09:14, David Weinehall
<david.weinehall at linux.intel.com> wrote:
> Move power management related code to a separate library.
> Initially this is done only for workarounds that apply to external
> components.  Modify the users of such workarounds accordingly.
> This currently involves HD audio and SATA link power management.
> For SATA link PM there's also code to save the previous settings,
> to allow for resetting the values after we've finished testing.
>
> Signed-off-by: David Weinehall <david.weinehall at intel.com>
> ---
>  lib/Makefile.sources |   2 +
>  lib/igt.h            |   1 +
>  lib/igt_aux.c        |  15 +---
>  lib/igt_pm.c         | 233 +++++++++++++++++++++++++++++++++++++++++++++++++++
>  lib/igt_pm.h         |  31 +++++++
>  tests/pm_lpsp.c      |  25 +-----
>  tests/pm_rpm.c       |  29 ++-----

igt_pm.xml needs including in
docs/reference/intel-gpu-tools/intel-gpu-tools-docs.xml to make sure
the new documentation is included in the output.


>  7 files changed, 279 insertions(+), 57 deletions(-)
>  create mode 100644 lib/igt_pm.c
>  create mode 100644 lib/igt_pm.h
>
> diff --git a/lib/Makefile.sources b/lib/Makefile.sources
> index 4999868052b1..2f0eb2075e14 100644
> --- a/lib/Makefile.sources
> +++ b/lib/Makefile.sources
> @@ -60,6 +60,8 @@ libintel_tools_la_SOURCES =   \
>         igt_core.h              \
>         igt_draw.c              \
>         igt_draw.h              \
> +       igt_pm.c        \
> +       igt_pm.h        \
>         $(NULL)
>
>  .PHONY: version.h.tmp
> diff --git a/lib/igt.h b/lib/igt.h
> index 3be25511bb77..b8792141ee3c 100644
> --- a/lib/igt.h
> +++ b/lib/igt.h
> @@ -44,5 +44,6 @@
>  #include "media_fill.h"
>  #include "media_spin.h"
>  #include "rendercopy.h"
> +#include "igt_pm.h"

It'd be nice to keep the list alphabetical.


>
>  #endif /* IGT_H */
> diff --git a/lib/igt_aux.c b/lib/igt_aux.c
> index 4d08d68bb932..cd7f14649fe2 100644
> --- a/lib/igt_aux.c
> +++ b/lib/igt_aux.c
> @@ -59,6 +59,7 @@
>  #include "intel_reg.h"
>  #include "ioctl_wrappers.h"
>  #include "igt_kms.h"
> +#include "igt_pm.h"
>
>  /**
>   * SECTION:igt_aux
> @@ -531,19 +532,7 @@ bool igt_setup_runtime_pm(void)
>         if (pm_status_fd >= 0)
>                 return true;
>
> -       /* The Audio driver can get runtime PM references, so we need to make
> -        * sure its runtime PM is enabled, so it can release the refs and
> -        * actually enable us to runtime suspend. */
> -       fd = open("/sys/module/snd_hda_intel/parameters/power_save", O_WRONLY);
> -       if (fd >= 0) {
> -               igt_assert(write(fd, "1\n", 2) == 2);
> -               close(fd);
> -       }
> -       fd = open("/sys/bus/pci/devices/0000:00:03.0/power/control", O_WRONLY);
> -       if (fd >= 0) {
> -               igt_assert(write(fd, "auto\n", 5) == 5);
> -               close(fd);
> -       }
> +       igt_pm_enable_audio_runtime_pm();
>
>         /* 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
> diff --git a/lib/igt_pm.c b/lib/igt_pm.c
> new file mode 100644
> index 000000000000..f2e13ba6a44e
> --- /dev/null
> +++ b/lib/igt_pm.c
> @@ -0,0 +1,233 @@
> +/*
> + * Copyright © 2013, 2015 Intel Corporation
> + *
> + * Permission is hereby granted, free of charge, to any person obtaining a
> + * copy of this software and associated documentation files (the "Software"),
> + * to deal in the Software without restriction, including without limitation
> + * the rights to use, copy, modify, merge, publish, distribute, sublicense,
> + * and/or sell copies of the Software, and to permit persons to whom the
> + * Software is furnished to do so, subject to the following conditions:
> + *
> + * The above copyright notice and this permission notice (including the next
> + * paragraph) shall be included in all copies or substantial portions of the
> + * Software.
> + *
> + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
> + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
> + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
> + * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
> + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
> + * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
> + * IN THE SOFTWARE.
> + *
> + * Authors:
> + *    Paulo Zanoni <paulo.r.zanoni at intel.com>
> + *    David Weinehall <david.weinehall at intel.com>
> + *
> + */
> +#include <fcntl.h>
> +#include <stdio.h>
> +#include <limits.h>
> +#include <stdlib.h>
> +#include <string.h>
> +#include <unistd.h>
> +#include <sys/stat.h>
> +#include <sys/types.h>
> +
> +#include "drmtest.h"
> +#include "igt_pm.h"
> +
> +enum {
> +       POLICY_UNKNOWN = -1,
> +       POLICY_MAX_PERFORMANCE = 0,
> +       POLICY_MEDIUM_POWER = 1,
> +       POLICY_MIN_POWER = 2
> +};
> +
> +#define MAX_PERFORMANCE_STR    "max_performance\n"
> +#define MEDIUM_POWER_STR       "medium_power\n"
> +#define MIN_POWER_STR          "min_power\n"
> +/* Remember to fix this if adding longer strings */
> +#define MAX_POLICY_STRLEN      strlen(MAX_PERFORMANCE_STR)
> +
> +/**
> + * SECTION:igt_pm
> + * @short_description: Power Management related helpers
> + * @title: IGT PM

"Power Management" would be more descriptive for the title.


> + * @include: igt_pm.h

Since igt_pm.h is included in igt.h, this only needs to mention igt.h.


> + *
> + * This library provides various helpers to enable power management,
> + * and in some cases subsequently allow restoring of the old behaviour of,

Should "of," be "and" here?


> + * various external components that by default are set up in a way
> + * that interferes with the testing of our power management functionality.
> + */
> +/**
> + * igt_pm_enable_audio_runtime_pm:
> + *
> + * We know that if we don't enable audio runtime PM, snd_hda_intel will never
> + * release its power well refcount, and we'll never reach the LPSP sate.
> + * There's no guarantee that it will release the power well if we enable
> + * runtime PM, but at least we can try.
> + *
> + * We don't have any assertions on open since the user may not even have
> + * snd_hda_intel loaded, which is not a problem.
> + */
> +void igt_pm_enable_audio_runtime_pm(void)
> +{
> +       int fd;
> +
> +       fd = open("/sys/module/snd_hda_intel/parameters/power_save", O_WRONLY);
> +       if (fd >= 0) {
> +               igt_assert_eq(write(fd, "1\n", 2), 2);
> +               close(fd);
> +       }
> +       fd = open("/sys/bus/pci/devices/0000:00:03.0/power/control", O_WRONLY);
> +       if (fd >= 0) {
> +               igt_assert_eq(write(fd, "auto\n", 5), 5);
> +               close(fd);
> +       }
> +       /* Give some time for it to react. */
> +       sleep(1);
> +}
> +
> +/**
> + * igt_pm_enable_sata_link_power_management:
> + *
> + * Enable the min_power policy for SATA link power management.
> + * Without this we cannot reach deep runtime power states.
> + *
> + * We don't have any assertions on open since the system might not have
> + * a SATA host.
> + *
> + * Returns:
> + * An opaque pointer to the data needed to restore the default values
> + * after the test has terminated, or NULL if SATA link power management
> + * is not supported. This pointer should be freed when no longer used
> + * (typically after having called restore_sata_link_power_mananagement).

"management" is spelt incorrectly here. Also, adding "()" to the end
of the full function name will create a link to that function.


> + */
> +int8_t *igt_pm_enable_sata_link_power_management(void)
> +{
> +       int fd, i;
> +       ssize_t len;
> +       char *buf;
> +       char *file_name;
> +       int8_t *link_pm_policies = NULL;
> +
> +       file_name = malloc(PATH_MAX);
> +       buf = malloc(MAX_POLICY_STRLEN + 1);
> +
> +       for (i = 0; ; i++) {
> +               int8_t policy;
> +
> +               snprintf(file_name, PATH_MAX,
> +                        "/sys/class/scsi_host/host%d/link_power_management_policy",
> +                        i);
> +
> +               fd = open(file_name, O_RDWR);
> +               if (fd < 0)
> +                       break;
> +
> +               len = read(fd, buf, MAX_POLICY_STRLEN);
> +               buf[len] = '\0';
> +
> +               if (!strncmp(MAX_PERFORMANCE_STR, buf,
> +                            strlen(MAX_PERFORMANCE_STR)))
> +                       policy = POLICY_MAX_PERFORMANCE;
> +               else if (!strncmp(MEDIUM_POWER_STR, buf,
> +                                 strlen(MEDIUM_POWER_STR)))
> +                       policy = POLICY_MEDIUM_POWER;
> +               else if (!strncmp(MIN_POWER_STR, buf,
> +                                 strlen(MIN_POWER_STR)))
> +                       policy = POLICY_MIN_POWER;
> +               else
> +                       policy = POLICY_UNKNOWN;
> +
> +               if (!(i % 256))
> +                       link_pm_policies = realloc(link_pm_policies,
> +                                                  (i / 256 + 1) * 256 + 1);
> +
> +               link_pm_policies[i] = policy;
> +               link_pm_policies[i + 1] = 0;
> +
> +               /* If the policy is something we don't know about,
> +                * don't touch it, since we might potentially break things.
> +                * And we obviously don't need to touch anything if the
> +                * setting is already correct...
> +                */
> +               if (policy != POLICY_UNKNOWN &&
> +                   policy != POLICY_MIN_POWER) {
> +                       lseek(fd, 0, SEEK_SET);
> +                       igt_assert_eq(write(fd, MIN_POWER_STR,
> +                                           strlen(MIN_POWER_STR)),
> +                                     strlen(MIN_POWER_STR));
> +               }
> +               close(fd);
> +       }
> +       free(buf);
> +       free(file_name);
> +
> +       return link_pm_policies;
> +}
> +
> +/**
> + * it_pm_restore_sata_link_power_management:

igt_ prefix needs fixing here.


> + * @pm_data: An opaque pointer with saved link PM policies;
> + *           If NULL is passed we force enable the "max_performance" policy.
> + *
> + * Restore the link power management policies to the values
> + * prior to enabling min_power.
> + *
> + * Caveat: If the system supports hotplugging and hotplugging takes
> + *         place during our testing so that the hosts change numbers
> + *         we might restore the settings to the wrong hosts.
> + */
> +void igt_pm_restore_sata_link_power_management(int8_t *pm_data)
> +{
> +       int fd, i;
> +       char *file_name;
> +
> +       /* Disk runtime PM policies. */
> +       file_name = malloc(PATH_MAX);
> +       for (i = 0; ; i++) {
> +               int8_t policy;
> +
> +               if (!pm_data)
> +                       policy = POLICY_MAX_PERFORMANCE;
> +               else if (pm_data[i] == POLICY_UNKNOWN)
> +                       continue;
> +               else
> +                       policy = pm_data[i];
> +
> +               snprintf(file_name, PATH_MAX,
> +                        "/sys/class/scsi_host/host%d/link_power_management_policy",
> +                        i);
> +
> +               fd = open(file_name, O_WRONLY);
> +               if (fd < 0)
> +                       break;
> +
> +               switch (policy) {
> +               default:
> +               case POLICY_MAX_PERFORMANCE:
> +                       igt_assert_eq(write(fd, MAX_PERFORMANCE_STR,
> +                                           strlen(MAX_PERFORMANCE_STR)),
> +                                     strlen(MAX_PERFORMANCE_STR));
> +                       break;
> +
> +               case POLICY_MEDIUM_POWER:
> +                       igt_assert_eq(write(fd, MEDIUM_POWER_STR,
> +                                           strlen(MEDIUM_POWER_STR)),
> +                                     strlen(MEDIUM_POWER_STR));
> +                       break;
> +
> +               case POLICY_MIN_POWER:
> +                       igt_assert_eq(write(fd, MIN_POWER_STR,
> +                                           strlen(MIN_POWER_STR)),
> +                                     strlen(MIN_POWER_STR));
> +                       break;
> +               }
> +
> +               close(fd);
> +       }
> +       free(file_name);
> +}
> diff --git a/lib/igt_pm.h b/lib/igt_pm.h
> new file mode 100644
> index 000000000000..c14ff1f7a0ef
> --- /dev/null
> +++ b/lib/igt_pm.h
> @@ -0,0 +1,31 @@
> +/*
> + * Copyright © 2015 Intel Corporation
> + *
> + * Permission is hereby granted, free of charge, to any person obtaining a
> + * copy of this software and associated documentation files (the "Software"),
> + * to deal in the Software without restriction, including without limitation
> + * the rights to use, copy, modify, merge, publish, distribute, sublicense,
> + * and/or sell copies of the Software, and to permit persons to whom the
> + * Software is furnished to do so, subject to the following conditions:
> + *
> + * The above copyright notice and this permission notice (including the next
> + * paragraph) shall be included in all copies or substantial portions of the
> + * Software.
> + *
> + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
> + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
> + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
> + * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
> + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
> + * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
> + * IN THE SOFTWARE.
> + */
> +
> +#ifndef IGT_PM_H
> +#define IGT_PM_H
> +
> +void igt_pm_enable_audio_runtime_pm(void);
> +int8_t *igt_pm_enable_sata_link_power_management(void);
> +void igt_pm_restore_sata_link_power_management(int8_t *pm_data);
> +
> +#endif /* IGT_PM_H */
> diff --git a/tests/pm_lpsp.c b/tests/pm_lpsp.c
> index 257ae1b8b1d9..6cb697ed0bd5 100644
> --- a/tests/pm_lpsp.c
> +++ b/tests/pm_lpsp.c
> @@ -31,29 +31,6 @@
>  #include <unistd.h>
>
>
> -/* We know that if we don't enable audio runtime PM, snd_hda_intel will never
> - * release its power well refcount, and we'll never reach the LPSP sate. OTOH
> - * there's no guarantee that it will release the power well if we enable runtime
> - * PM, but at least we can try.  We don't have any assertions since the user may
> - * not even have snd_hda_intel loaded, which is not a problem. */
> -static void disable_audio_runtime_pm(void)
> -{
> -       int fd;
> -
> -       fd = open("/sys/module/snd_hda_intel/parameters/power_save", O_WRONLY);
> -       if (fd >= 0) {
> -               igt_assert_eq(write(fd, "1\n", 2), 2);
> -               close(fd);
> -       }
> -       fd = open("/sys/bus/pci/devices/0000:00:03.0/power/control", O_WRONLY);
> -       if (fd >= 0) {
> -               igt_assert_eq(write(fd, "auto\n", 5), 5);
> -               close(fd);
> -       }
> -       /* Give some time for it to react. */
> -       sleep(1);
> -}
> -
>  static bool supports_lpsp(uint32_t devid)
>  {
>         return IS_HASWELL(devid) || IS_BROADWELL(devid);
> @@ -234,7 +211,7 @@ igt_main
>                         drm_connectors[i] = drmModeGetConnectorCurrent(drm_fd,
>                                                         drm_res->connectors[i]);
>
> -               disable_audio_runtime_pm();
> +               igt_pm_enable_audio_runtime_pm();
>
>                 igt_require(supports_lpsp(devid));
>
> diff --git a/tests/pm_rpm.c b/tests/pm_rpm.c
> index 55fdb31cb723..6d695a5e3e01 100644
> --- a/tests/pm_rpm.c
> +++ b/tests/pm_rpm.c
> @@ -1,5 +1,5 @@
>  /*
> - * Copyright © 2013 Intel Corporation
> + * Copyright © 2013, 2015 Intel Corporation
>   *
>   * Permission is hereby granted, free of charge, to any person obtaining a
>   * copy of this software and associated documentation files (the "Software"),
> @@ -111,6 +111,8 @@ struct modeset_params lpsp_mode_params;
>  struct modeset_params non_lpsp_mode_params;
>  struct modeset_params *default_mode_params;
>
> +static int8_t *pm_data = NULL;
> +
>  /* If the read fails, then the machine doesn't support PC8+ residencies. */
>  static bool supports_pc8_plus_residencies(void)
>  {
> @@ -677,25 +679,7 @@ static void setup_pc8(void)
>   * anything, just try to help with the more common problems. */
>  static void setup_non_graphics_runtime_pm(void)
>  {
> -       int fd, i;
> -       char *file_name;
> -
> -       /* Disk runtime PM policies. */
> -       file_name = malloc(PATH_MAX);
> -       for (i = 0; ; i++) {
> -
> -               snprintf(file_name, PATH_MAX,
> -                        "/sys/class/scsi_host/host%d/link_power_management_policy",
> -                        i);
> -
> -               fd = open(file_name, O_WRONLY);
> -               if (fd < 0)
> -                       break;
> -
> -               igt_assert(write(fd, "min_power\n", 10) == 10);
> -               close(fd);
> -       }
> -       free(file_name);
> +       pm_data = igt_pm_enable_sata_link_power_management();

Could this call be moved into setup_environment and then this function
(and comment above) be removed?


>  }
>
>  static void setup_environment(void)
> @@ -713,11 +697,16 @@ static void setup_environment(void)
>         igt_info("PC8 residency support: %d\n", has_pc8);
>
>         igt_require(has_runtime_pm);
> +}
>
> +static void restore_environment(void)
> +{
> +       igt_pm_restore_sata_link_power_management(pm_data);
>  }
>
>  static void teardown_environment(void)
>  {
> +       restore_environment();

igt_pm_restore_sata_link_power_management could be called directly here.

Also, pm_data is not freed.


>         fini_mode_set_data(&ms_data);
>         drmClose(drm_fd);
>         close(msr_fd);
> --
> 2.6.3
>
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