[Intel-gfx] [PATCH 1/3] drm/i915: Reorder hpd init vs. display resume

[Ville Syrjala]

From: Ville Syrjälä <ville.syrjala at linux.intel.com>

Currently we call .hpd_irq_setup() directly just before display
resume, and follow it with another call via intel_hpd_init()
just afterwards. Assuming the hpd pins are marked as enabled
during the open-coded call these two things do exactly the
same thing (ie. enable HPD interrupts). Which even makes sense
since we definitely need working HPD interrupts for MST sideband
during the display resume.

So let's just nuke the open-coded call and move the intel_hpd_init()
call earlier.

If we really would like to prevent all *long* HPD processing during
display resume we'd need some kind of software mechanism to simply
ignore all long HPDs. Currently we appear to have that just for
fbdev via ifbdev->hpd_suspended. Since we aren't exploding left and
right all the time I guess that's mostly sufficient.

Signed-off-by: Ville Syrjälä <ville.syrjala at linux.intel.com>
---
 drivers/gpu/drm/i915/display/intel_display.c |  8 +-------
 drivers/gpu/drm/i915/i915_drv.c              | 16 ++--------------
 2 files changed, 3 insertions(+), 21 deletions(-)

diff --git a/drivers/gpu/drm/i915/display/intel_display.c b/drivers/gpu/drm/i915/display/intel_display.c
index 907e1d155443..87df7167433f 100644
--- a/drivers/gpu/drm/i915/display/intel_display.c
+++ b/drivers/gpu/drm/i915/display/intel_display.c
@@ -5036,18 +5036,12 @@ void intel_finish_reset(struct drm_i915_private *dev_priv)
 		intel_pps_unlock_regs_wa(dev_priv);
 		intel_modeset_init_hw(dev_priv);
 		intel_init_clock_gating(dev_priv);
-
-		spin_lock_irq(&dev_priv->irq_lock);
-		if (dev_priv->display.hpd_irq_setup)
-			dev_priv->display.hpd_irq_setup(dev_priv);
-		spin_unlock_irq(&dev_priv->irq_lock);
+		intel_hpd_init(dev_priv);
 
 		ret = __intel_display_resume(dev, state, ctx);
 		if (ret)
 			drm_err(&dev_priv->drm,
 				"Restoring old state failed with %i\n", ret);
-
-		intel_hpd_init(dev_priv);
 	}
 
 	drm_atomic_state_put(state);
diff --git a/drivers/gpu/drm/i915/i915_drv.c b/drivers/gpu/drm/i915/i915_drv.c
index ebc15066d108..b2a050d916e3 100644
--- a/drivers/gpu/drm/i915/i915_drv.c
+++ b/drivers/gpu/drm/i915/i915_drv.c
@@ -1226,26 +1226,14 @@ static int i915_drm_resume(struct drm_device *dev)
 
 	intel_modeset_init_hw(dev_priv);
 	intel_init_clock_gating(dev_priv);
+	intel_hpd_init(dev_priv);
 
-	spin_lock_irq(&dev_priv->irq_lock);
-	if (dev_priv->display.hpd_irq_setup)
-		dev_priv->display.hpd_irq_setup(dev_priv);
-	spin_unlock_irq(&dev_priv->irq_lock);
-
+	/* MST sideband requires HPD interrupts enabled */
 	intel_dp_mst_resume(dev_priv);
-
 	intel_display_resume(dev);
 
 	drm_kms_helper_poll_enable(dev);
 
-	/*
-	 * ... but also need to make sure that hotplug processing
-	 * doesn't cause havoc. Like in the driver load code we don't
-	 * bother with the tiny race here where we might lose hotplug
-	 * notifications.
-	 * */
-	intel_hpd_init(dev_priv);
-
 	intel_opregion_resume(dev_priv);
 
 	intel_fbdev_set_suspend(dev, FBINFO_STATE_RUNNING, false);
-- 
2.26.2