[Intel-gfx] [PATCH] drm/i915: freeze display before the interrupts and GT

[Paulo Zanoni]

From: Paulo Zanoni <paulo.r.zanoni at intel.com>

Since we started using intel_runtime_pm_disable_interrupts() at normal
(non-runtime) suspend/resume, we had to remove a WARN from
ironlake_disable_display_irq to avoid a case where we were doing the
correct thing and the WARN was not really needed. The problem is that
the WARN was useful in other cases, and its removal can hide some bugs
that we would catch automatically.

To be able to add back the WARN, we have to call intel_crtc_control()
before interrupts are disabled, which is what this patch currently
does.

Also notice that Ville's patch from the Watermarks series "drm/i915:
Leave interrupts enabled while disabling crtcs during suspend" also
did a change that's equivalent to the one we're doing on this patch,
with the exception that its original patch, when applied to the
current tree, procduces a WARN.

Related commits:

commit daa390e5ee45cc051d6bf37b296901f2f92b002d
Author: Jesse Barnes <jbarnes at virtuousgeek.org>
    drm/i915: don't warn if IRQs are disabled when shutting down display IRQs

commit e11aa362308f5de467ce355a2a2471321b15a35c
Author: Jesse Barnes <jbarnes at virtuousgeek.org>
    drm/i915: use runtime irq suspend/resume in freeze/thaw

Cc: Ville Syrjälä <ville.syrjala at linux.intel.com>
Cc: Jesse Barnes <jbarnes at virtuousgeek.org>
Signed-off-by: Paulo Zanoni <paulo.r.zanoni at intel.com>
---
 drivers/gpu/drm/i915/i915_drv.c | 11 +++++------
 drivers/gpu/drm/i915/i915_irq.c |  2 +-
 2 files changed, 6 insertions(+), 7 deletions(-)

No need to revert anything :)

diff --git a/drivers/gpu/drm/i915/i915_drv.c b/drivers/gpu/drm/i915/i915_drv.c
index 3315358..63675bf 100644
--- a/drivers/gpu/drm/i915/i915_drv.c
+++ b/drivers/gpu/drm/i915/i915_drv.c
@@ -520,12 +520,6 @@ static int i915_drm_freeze(struct drm_device *dev)
 			return error;
 		}
 
-		flush_delayed_work(&dev_priv->rps.delayed_resume_work);
-
-		intel_runtime_pm_disable_interrupts(dev);
-
-		intel_suspend_gt_powersave(dev);
-
 		/*
 		 * Disable CRTCs directly since we want to preserve sw state
 		 * for _thaw. Also, power gate the CRTC power wells.
@@ -535,6 +529,11 @@ static int i915_drm_freeze(struct drm_device *dev)
 			intel_crtc_control(crtc, false);
 		drm_modeset_unlock_all(dev);
 
+		flush_delayed_work(&dev_priv->rps.delayed_resume_work);
+		intel_runtime_pm_disable_interrupts(dev);
+
+		intel_suspend_gt_powersave(dev);
+
 		intel_modeset_suspend_hw(dev);
 	}
 
diff --git a/drivers/gpu/drm/i915/i915_irq.c b/drivers/gpu/drm/i915/i915_irq.c
index 20c777c..af231ba 100644
--- a/drivers/gpu/drm/i915/i915_irq.c
+++ b/drivers/gpu/drm/i915/i915_irq.c
@@ -151,7 +151,7 @@ ironlake_disable_display_irq(struct drm_i915_private *dev_priv, u32 mask)
 {
 	assert_spin_locked(&dev_priv->irq_lock);
 
-	if (!intel_irqs_enabled(dev_priv))
+	if (WARN_ON(!intel_irqs_enabled(dev_priv)))
 		return;
 
 	if ((dev_priv->irq_mask & mask) != mask) {
-- 
2.0.0