[Intel-gfx] [PATCH 7/8] drm/i915/skl: Disallow tiling changes during page flip

[Rodrigo Vivi]

From: Tvrtko Ursulin <tvrtko.ursulin at intel.com>

It would require watermark reprogramming which we do not want to do.

Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin at intel.com>
Cc: Daniel Vetter <daniel.vetter at ffwll.ch>
Cc: Sonika Jindal <sonika.jindal at intel.com>
Cc: Damien Lespiau <damien.lespiau at intel.com>
Cc: Chris Wilson <chris at chris-wilson.co.uk>
Tested-By: Intel Graphics QA PRTS (Patch Regression Test System Contact: shuang.he at intel.com)
Signed-off-by: Rodrigo Vivi <rodrigo.vivi at intel.com>
---
 drivers/gpu/drm/i915/intel_display.c | 17 +++++++++++++++++
 1 file changed, 17 insertions(+)

diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index 489a134..a2b7259 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -10896,6 +10896,15 @@ void intel_check_page_flip(struct drm_device *dev, int pipe)
 	spin_unlock(&dev->event_lock);
 }
 
+static bool intel_is_y_tiled(uint64_t fb_modifier)
+{
+	if (fb_modifier == I915_FORMAT_MOD_Y_TILED ||
+	    fb_modifier == I915_FORMAT_MOD_Yf_TILED)
+		return true;
+
+	return false;
+}
+
 static int intel_crtc_page_flip(struct drm_crtc *crtc,
 				struct drm_framebuffer *fb,
 				struct drm_pending_vblank_event *event,
@@ -11025,6 +11034,14 @@ static int intel_crtc_page_flip(struct drm_crtc *crtc,
 						  + intel_crtc->dspaddr_offset;
 
 	if (mmio_flip) {
+		/* Temporarily embedding knowledge of disallowed tiling mode
+		 * transition which would require watermark reprogramming.
+		 */
+		if (intel_is_y_tiled(old_fb->modifier[0]) !=
+		    intel_is_y_tiled(fb->modifier[0])) {
+			ret = -EINVAL;
+			goto cleanup_unpin;
+		}
 		ret = intel_queue_mmio_flip(dev, crtc, fb, obj, ring,
 					    page_flip_flags);
 		if (ret)
-- 
2.1.0