[Intel-gfx] [PATCH] drm/i915: add modeset_global_pipes callback for global config adjustments

[Jesse Barnes]

In some cases we may need to turn off more pipes than just the ones
affected by a connector or encoder change, probably due to modifying
some global resource that requires all pipes to shut down.  Add a hook
for this purpose to allow platform code to adjust the prepare_pipes
mask, which allows otherwise active pipes to get shut down for the
duration of the mode set, then restored at the end.

Signed-off-by: Jesse Barnes <jbarnes at virtuousgeek.org>
---
 drivers/gpu/drm/i915/i915_drv.h      | 12 ++++++++++++
 drivers/gpu/drm/i915/intel_display.c |  7 +++++++
 2 files changed, 19 insertions(+)

diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index 5edf9bb..7530cd4 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -380,6 +380,18 @@ struct drm_i915_display_funcs {
 				 struct drm_crtc *crtc,
 				 uint32_t sprite_width, int pixel_size,
 				 bool enable, bool scaled);
+	/**
+	 * modeset_global_pipes - figure out which pipes need to be disabled
+	 * @dev: drm device
+	 * @prepare_pipes: bitmask of pipes to disable
+	 *
+	 * In some cases, adjusting a global resource may require shutting
+	 * down seemingly unrelated pipes on a mode set.  This function
+	 * should determine that and adjust the prepare_pipes bitmask
+	 * as needed.
+	 */
+	void (*modeset_global_pipes)(struct drm_device *dev,
+				     unsigned *prepare_pipes);
 	void (*modeset_global_resources)(struct drm_device *dev);
 	/* Returns the active state of the crtc, and if the crtc is active,
 	 * fills out the pipe-config with the hw state. */
diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index 606a594..faa7548 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -9298,6 +9298,13 @@ static int __intel_set_mode(struct drm_crtc *crtc,
 	intel_modeset_affected_pipes(crtc, &modeset_pipes,
 				     &prepare_pipes, &disable_pipes);
 
+	/*
+	 * See if the config requires any additional preparation, e.g.
+	 * to adjust global state with pipes off.
+	 */
+	if (dev_priv->display.modeset_global_pipes)
+		dev_priv->display.modeset_global_pipes(dev, &prepare_pipes);
+
 	*saved_hwmode = crtc->hwmode;
 	*saved_mode = crtc->mode;
 
-- 
1.8.3.1