[Intel-gfx] [PATCH] drm/i915: Avoid vblank counter for gen9+

[Rodrigo Vivi]

Framecounter register is read-only so DMC cannot restore it
after exiting DC5 and DC6.

Easiest way to go is to avoid the counter and use vblank
interruptions for this platform and for all the following
ones since DMC came to stay. At least while we can't change
this register to read-write.

Signed-off-by: Rodrigo Vivi <rodrigo.vivi at intel.com>
---
 drivers/gpu/drm/i915/i915_irq.c | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/i915/i915_irq.c b/drivers/gpu/drm/i915/i915_irq.c
index 25a8937..c294a4b 100644
--- a/drivers/gpu/drm/i915/i915_irq.c
+++ b/drivers/gpu/drm/i915/i915_irq.c
@@ -4556,7 +4556,10 @@ void intel_irq_init(struct drm_i915_private *dev_priv)
 
 	pm_qos_add_request(&dev_priv->pm_qos, PM_QOS_CPU_DMA_LATENCY, PM_QOS_DEFAULT_VALUE);
 
-	if (IS_GEN2(dev_priv)) {
+	if (INTEL_INFO(dev_priv)->gen >= 9) {
+		dev->max_vblank_count = 0;
+		dev->driver->get_vblank_counter = g4x_get_vblank_counter;
+	} else if (IS_GEN2(dev_priv)) {
 		dev->max_vblank_count = 0;
 		dev->driver->get_vblank_counter = i8xx_get_vblank_counter;
 	} else if (IS_G4X(dev_priv) || INTEL_INFO(dev_priv)->gen >= 5) {
@@ -4572,7 +4575,7 @@ void intel_irq_init(struct drm_i915_private *dev_priv)
 	 * Gen2 doesn't have a hardware frame counter and so depends on
 	 * vblank interrupts to produce sane vblank seuquence numbers.
 	 */
-	if (!IS_GEN2(dev_priv))
+	if (!IS_GEN2(dev_priv) && !INTEL_INFO(dev_priv)->gen >= 9)
 		dev->vblank_disable_immediate = true;
 
 	dev->driver->get_vblank_timestamp = i915_get_vblank_timestamp;
-- 
2.4.3