Re: [Intel-gfx] [igt-dev] [PATCH i-g-t] tests/i915_pm_freq_api: Add a suspend subtest

[Belgaumkar, Vinay]

On 6/7/2023 2:12 PM, Dixit, Ashutosh wrote:
On Tue, 06 Jun 2023 13:35:35 -0700, Vinay Belgaumkar wrote:
Hi Vinay,

Verify that SLPC API works as expected after a suspend.

Signed-off-by: Vinay Belgaumkar <vinay.belgaum...@intel.com>
---
  tests/i915/i915_pm_freq_api.c | 30 ++++++++++++++++++++++++++++++
  1 file changed, 30 insertions(+)

diff --git a/tests/i915/i915_pm_freq_api.c b/tests/i915/i915_pm_freq_api.c
index 9005cd220..f35f1f8e0 100644
--- a/tests/i915/i915_pm_freq_api.c
+++ b/tests/i915/i915_pm_freq_api.c
@@ -18,6 +18,9 @@
   *
   * SUBTEST: freq-reset
   * Description: Test basic freq API works after a reset
+ *
+ * SUBTEST: freq-suspend
+ * Description: Test basic freq API works after a runtime suspend
   */

  IGT_TEST_DESCRIPTION("Test SLPC freq API");
@@ -99,6 +102,24 @@ static void test_reset(int i915, int dirfd, int gt)
        igt_assert(get_freq(dirfd, RPS_MAX_FREQ_MHZ) == rpn);
  }

+static void test_suspend(int i915, int dirfd, int gt)
+{
+       uint32_t rpn = get_freq(dirfd, RPS_RPn_FREQ_MHZ);
+
+       igt_assert(set_freq(dirfd, RPS_MIN_FREQ_MHZ, rpn) > 0);
+       igt_assert(set_freq(dirfd, RPS_MAX_FREQ_MHZ, rpn) > 0);
+       usleep(ACT_FREQ_LATENCY_US);
+       igt_assert(get_freq(dirfd, RPS_MIN_FREQ_MHZ) == rpn);
+       igt_assert(get_freq(dirfd, RPS_MAX_FREQ_MHZ) == rpn);
+
+       /* Manually trigger a suspend */
+       igt_system_suspend_autoresume(SUSPEND_STATE_S3,
+                                     SUSPEND_TEST_NONE);
+
+       igt_assert(get_freq(dirfd, RPS_MIN_FREQ_MHZ) == rpn);
+       igt_assert(get_freq(dirfd, RPS_MAX_FREQ_MHZ) == rpn);
I am wondering what the purpose/value of this test (and also "freq-reset")
is?  How can the "set" min/max set freq (which are just input settings)
change whether or not there is a suspend/resume or a reset? Especially when
we just return cached min/max values from i915?

It is mainly checking that we don't smother the softlimit during a reset 
or suspend flow. In addition, it also tests the read/write interface 
works as expected after those events.

Thanks,

Vinay.


Thanks.
--
Ashutosh


+}
+
  igt_main
  {
        int i915 = -1;
@@ -143,6 +164,15 @@ igt_main
                                test_reset(i915, dirfd, gt);
        }

+       igt_describe("Test basic freq API works after suspend");
+       igt_subtest_with_dynamic_f("freq-suspend") {
+               int dirfd, gt;
+
+               for_each_sysfs_gt_dirfd(i915, dirfd, gt)
+                       igt_dynamic_f("gt%u", gt)
+                               test_suspend(i915, dirfd, gt);
+       }
+
        igt_fixture {
                int dirfd, gt;
                /* Restore frequencies */
--
2.38.1