[Intel-gfx] [PATCH v2] drm/i915: Fix init_clock_gating for resume

[Ville Syrjala]

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

Moving the init_clock_gating() call from intel_modeset_init_hw() to
intel_modeset_gem_init() had an unintended effect of not applying
some workarounds on resume. This, for example, cause some kind of
corruption to appear at the top of my IVB Thinkpad X1 Carbon LVDS
screen after hibernation. Fix the problem by explicitly calling
init_clock_gating() from the resume path.

I really hope this doesn't break something else again. At least
the problems reported at https://bugs.freedesktop.org/show_bug.cgi?id=103549
didn't make a comeback, even after a hibernate cycle.

v2: Reorder the init_clock_gating vs. modeset_init_hw to match
    the display reset path (Rodrigo)

Cc: stable at vger.kernel.org
Cc: Chris Wilson <chris at chris-wilson.co.uk>
Cc: Rodrigo Vivi <rodrigo.vivi at intel.com>
Fixes: 6ac43272768c ("drm/i915: Move init_clock_gating() back to where it was")
Signed-off-by: Ville Syrjälä <ville.syrjala at linux.intel.com>
Reviewed-by: Rodrigo Vivi <rodrigo.vivi at intel.com>
---
 drivers/gpu/drm/i915/i915_drv.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/gpu/drm/i915/i915_drv.c b/drivers/gpu/drm/i915/i915_drv.c
index 3423d873123a..fb584b821fb3 100644
--- a/drivers/gpu/drm/i915/i915_drv.c
+++ b/drivers/gpu/drm/i915/i915_drv.c
@@ -1709,6 +1709,7 @@ static int i915_drm_resume(struct drm_device *dev)
 	i915_gem_resume(dev_priv);
 
 	intel_modeset_init_hw(dev);
+	intel_init_clock_gating(dev_priv);
 
 	spin_lock_irq(&dev_priv->irq_lock);
 	if (dev_priv->display.hpd_irq_setup)
-- 
2.13.6