[PATCH v5] drm/i915/selftests: Implement frequency logging for energy reading validation

[Sk Anirban]

Introduce RC6 & RC0 frequency logging mechanism to ensure accurate
energy readings aimed at addressing GPU energy leaks and power
measurement failures.
This enhancement will help ensure the accuracy of energy readings.

v2:
  - Improved commit message.
v3:
  - Used pr_err log to display frequency (Anshuman)
  - Sorted headers alphabetically (Sai Teja)
v4:
  - Improved commit message
  - Fix pr_err log (Sai Teja)
v5:
  -Add error & debug logging for RC0 power and frequency checks (Anshuman)

Signed-off-by: Sk Anirban <sk.anir...@intel.com>
Reviewed-by: Sai Teja Pottumuttu <sai.teja.pottumu...@intel.com>
---
 drivers/gpu/drm/i915/gt/selftest_rc6.c | 20 ++++++++++++++++----
 1 file changed, 16 insertions(+), 4 deletions(-)

diff --git a/drivers/gpu/drm/i915/gt/selftest_rc6.c 
b/drivers/gpu/drm/i915/gt/selftest_rc6.c
index 1aa1446c8fb0..0cf86fed39ca 100644
--- a/drivers/gpu/drm/i915/gt/selftest_rc6.c
+++ b/drivers/gpu/drm/i915/gt/selftest_rc6.c
@@ -8,6 +8,7 @@
 #include "intel_gpu_commands.h"
 #include "intel_gt_requests.h"
 #include "intel_ring.h"
+#include "intel_rps.h"
 #include "selftest_rc6.h"
 
 #include "selftests/i915_random.h"
@@ -38,6 +39,9 @@ int live_rc6_manual(void *arg)
        ktime_t dt;
        u64 res[2];
        int err = 0;
+       u32 rc0_freq = 0;
+       u32 rc6_freq = 0;
+       struct intel_rps *rps = &gt->rps;
 
        /*
         * Our claim is that we can "encourage" the GPU to enter rc6 at will.
@@ -66,6 +70,7 @@ int live_rc6_manual(void *arg)
        rc0_power = librapl_energy_uJ() - rc0_power;
        dt = ktime_sub(ktime_get(), dt);
        res[1] = rc6_residency(rc6);
+       rc0_freq = intel_rps_read_actual_frequency(rps);
        if ((res[1] - res[0]) >> 10) {
                pr_err("RC6 residency increased by %lldus while disabled for 
1000ms!\n",
                       (res[1] - res[0]) >> 10);
@@ -77,9 +82,14 @@ int live_rc6_manual(void *arg)
                rc0_power = div64_u64(NSEC_PER_SEC * rc0_power,
                                      ktime_to_ns(dt));
                if (!rc0_power) {
-                       pr_err("No power measured while in RC0\n");
-                       err = -EINVAL;
-                       goto out_unlock;
+                       if (rc0_freq)
+                               pr_debug("No power measured while in RC0! GPU 
Freq: %u in RC0\n",
+                       rc0_freq);
+                       else {
+                               pr_err("No power and freq measured while in 
RC0\n");
+                               err = -EINVAL;
+                               goto out_unlock;
+                       }
                }
        }
 
@@ -91,6 +101,7 @@ int live_rc6_manual(void *arg)
        dt = ktime_get();
        rc6_power = librapl_energy_uJ();
        msleep(100);
+       rc6_freq = intel_rps_read_actual_frequency(rps);
        rc6_power = librapl_energy_uJ() - rc6_power;
        dt = ktime_sub(ktime_get(), dt);
        res[1] = rc6_residency(rc6);
@@ -108,7 +119,8 @@ int live_rc6_manual(void *arg)
                pr_info("GPU consumed %llduW in RC0 and %llduW in RC6\n",
                        rc0_power, rc6_power);
                if (2 * rc6_power > rc0_power) {
-                       pr_err("GPU leaked energy while in RC6!\n");
+                       pr_err("GPU leaked energy while in RC6! GPU Freq: %u in 
RC6 and %u in RC0\n",
+                              rc6_freq, rc0_freq);
                        err = -EINVAL;
                        goto out_unlock;
                }
-- 
2.34.1