drm/i915: Restore current RPS state after reset

Following commit 821ed7df6e2a ("drm/i915: Update reset path to fix
incomplete requests") we no longer mark the context as lost on reset as
we keep the requests (and contexts) alive. However, RPS remains reset
and we need to restore the current state to match the in-flight
requests.

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=97824
Fixes: 821ed7df6e2a ("drm/i915: Update reset path to fix incomplete requests")
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Mika Kuoppala <mika.kuoppala@intel.com>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Cc: Arun Siluvery <arun.siluvery@linux.intel.com>
Reviewed-by: Mika Kuoppala <mika.kuoppala@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20160921135108.29574-1-chris@chris-wilson.co.uk
(cherry picked from commit f2a91d1a6f5960c08f1ca60bd076f4dc020c50c6)
Signed-off-by: Jani Nikula <jani.nikula@intel.com>

3 files changed, 13 insertions, 9 deletions

diff --git a/drivers/gpu/drm/i915/i915_drv.c b/drivers/gpu/drm/i915/i915_drv.c
index 7f4e8adec8a8..8ae5853ea3c6 100644
--- a/drivers/gpu/drm/i915/i915_drv.c
+++ b/drivers/gpu/drm/i915/i915_drv.c
@@ -1786,15 +1786,6 @@ void i915_reset(struct drm_i915_private *dev_priv)
                 goto error;
         }
 
-        /*
-         * rps/rc6 re-init is necessary to restore state lost after the
-         * reset and the re-install of gt irqs. Skip for ironlake per
-         * previous concerns that it doesn't respond well to some forms
-         * of re-init after reset.
-         */
-        intel_sanitize_gt_powersave(dev_priv);
-        intel_autoenable_gt_powersave(dev_priv);
-
 wakeup:
         wake_up_bit(&error->flags, I915_RESET_IN_PROGRESS);
         return;
diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
index 2c8106758922..eb1ca8886bb9 100644
--- a/drivers/gpu/drm/i915/i915_gem.c
+++ b/drivers/gpu/drm/i915/i915_gem.c
@@ -2631,6 +2631,13 @@ void i915_gem_reset(struct drm_i915_private *dev_priv)
         mod_delayed_work(dev_priv->wq, &dev_priv->gt.idle_work, 0);
 
         i915_gem_restore_fences(&dev_priv->drm);
+
+        if (dev_priv->gt.awake) {
+                intel_sanitize_gt_powersave(dev_priv);
+                intel_enable_gt_powersave(dev_priv);
+                if (INTEL_GEN(dev_priv) >= 6)
+                        gen6_rps_busy(dev_priv);
+        }
 }
 
 static void nop_submit_request(struct drm_i915_gem_request *request)
diff --git a/drivers/gpu/drm/i915/i915_irq.c b/drivers/gpu/drm/i915/i915_irq.c
index c128fdbd24e4..13fae1c9dcc8 100644
--- a/drivers/gpu/drm/i915/i915_irq.c
+++ b/drivers/gpu/drm/i915/i915_irq.c
@@ -350,6 +350,9 @@ void gen6_reset_rps_interrupts(struct drm_i915_private *dev_priv)
 
 void gen6_enable_rps_interrupts(struct drm_i915_private *dev_priv)
 {
+        if (READ_ONCE(dev_priv->rps.interrupts_enabled))
+                return;
+
         spin_lock_irq(&dev_priv->irq_lock);
         WARN_ON_ONCE(dev_priv->rps.pm_iir);
         WARN_ON_ONCE(I915_READ(gen6_pm_iir(dev_priv)) & dev_priv->pm_rps_events);
@@ -368,6 +371,9 @@ u32 gen6_sanitize_rps_pm_mask(struct drm_i915_private *dev_priv, u32 mask)
 
 void gen6_disable_rps_interrupts(struct drm_i915_private *dev_priv)
 {
+        if (!READ_ONCE(dev_priv->rps.interrupts_enabled))
+                return;
+
         spin_lock_irq(&dev_priv->irq_lock);
         dev_priv->rps.interrupts_enabled = false;