drm/i915/gt: Update PMINTRMSK holding fw

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 <currojerez@riseup.net>
Suggested-by: Francisco Jerez <currojerez@riseup.net>
Fixes: 35cc7f3 ("drm/i915/gt: Use non-forcewake writes for RPS")
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Francisco Jerez <currojerez@riseup.net>
Cc: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Cc: Andi Shyti <andi.shyti@intel.com>
Reviewed-by: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Reviewed-by: Andi Shyti <andi.shyti@intel.com>
Reviewed-by: Francisco Jerez <currojerez@riseup.net>
Cc: <stable@vger.kernel.org> # v5.6+
Link: https://patchwork.freedesktop.org/patch/msgid/20200415170318.16771-2-chris@chris-wilson.co.uk
(cherry picked from commit a080bd9)
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>

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);