[Intel-gfx] [PATCH] drm/i915: Acquire RPM wakeref for KMS atomic commit

Chris Wilson chris at chris-wilson.co.uk
Sat Dec 19 01:58:43 PST 2015

Once all the preparations are complete, we are ready to write the
modesetting to the hardware. During this phase, we will be making lots
of HW register access, so take a top level wakeref to prevent an
unwarranted rpm suspend cycle mid-commit. Lower level functions should
be waking the individual power wells as required.

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=93439
Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
Cc: Imre Deak <imre.deak at intel.com>
 drivers/gpu/drm/i915/intel_display.c | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index abd2d2944022..60451c3932db 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -13470,6 +13470,13 @@ static int intel_atomic_commit(struct drm_device *dev,
 	drm_atomic_helper_swap_state(dev, state);
 	dev_priv->wm.config = to_intel_atomic_state(state)->wm_config;
+	/* Take a rpm wakeref for the duration of the commit. Lower level
+	 * functions should be acquiring the power wells for their own use,
+	 * we take this toplevel reference to prevent rpm suspend cycles
+	 * mid-commit.
+	 */
+	intel_runtime_pm_get(dev_priv);
 	for_each_crtc_in_state(state, crtc, crtc_state, i) {
 		struct intel_crtc *intel_crtc = to_intel_crtc(crtc);
@@ -13558,6 +13565,8 @@ static int intel_atomic_commit(struct drm_device *dev,
 	if (any_ms)
 		intel_modeset_check_state(dev, state);
+	intel_runtime_pm_put(dev_priv);
 	return 0;

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