If we use a non-forcewaked write to PMINTRMSK, it does not take effect
until much later, if at all, causing a loss of RPS interrupts and no GPU
reclocking, leaving the GPU running at the wrong frequency for long
periods of time.

Reported-by: Francisco Jerez <[email protected]>
Suggested-by: Francisco Jerez <[email protected]>
Fixes: 35cc7f32c298 ("drm/i915/gt: Use non-forcewake writes for RPS")
Signed-off-by: Chris Wilson <[email protected]>
Cc: Francisco Jerez <[email protected]>
Cc: Mika Kuoppala <[email protected]>
Cc: Andi Shyti <[email protected]>
Cc: <[email protected]> # v5.6+
---
 drivers/gpu/drm/i915/gt/intel_rps.c | 9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/i915/gt/intel_rps.c 
b/drivers/gpu/drm/i915/gt/intel_rps.c
index 86110458e2a7..6a3505467406 100644
--- a/drivers/gpu/drm/i915/gt/intel_rps.c
+++ b/drivers/gpu/drm/i915/gt/intel_rps.c
@@ -81,13 +81,14 @@ static void rps_enable_interrupts(struct intel_rps *rps)
                events = (GEN6_PM_RP_UP_THRESHOLD |
                          GEN6_PM_RP_DOWN_THRESHOLD |
                          GEN6_PM_RP_DOWN_TIMEOUT);
-
        WRITE_ONCE(rps->pm_events, events);
+
        spin_lock_irq(&gt->irq_lock);
        gen6_gt_pm_enable_irq(gt, rps->pm_events);
        spin_unlock_irq(&gt->irq_lock);
 
-       set(gt->uncore, GEN6_PMINTRMSK, rps_pm_mask(rps, rps->cur_freq));
+       intel_uncore_write(gt->uncore,
+                           GEN6_PMINTRMSK, rps_pm_mask(rps, rps->last_freq));
 }
 
 static void gen6_rps_reset_interrupts(struct intel_rps *rps)
@@ -120,7 +121,9 @@ static void rps_disable_interrupts(struct intel_rps *rps)
        struct intel_gt *gt = rps_to_gt(rps);
 
        WRITE_ONCE(rps->pm_events, 0);
-       set(gt->uncore, GEN6_PMINTRMSK, rps_pm_sanitize_mask(rps, ~0u));
+
+       intel_uncore_write(gt->uncore,
+                           GEN6_PMINTRMSK, rps_pm_sanitize_mask(rps, ~0u));
 
        spin_lock_irq(&gt->irq_lock);
        gen6_gt_pm_disable_irq(gt, GEN6_PM_RPS_EVENTS);
-- 
2.20.1

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