From ab8d66752a9c28cd6c94fa173feacdfc1554aa03 Mon Sep 17 00:00:00 2001 From: Tvrtko Ursulin Date: Mon, 2 Feb 2015 15:44:15 +0000 Subject: [PATCH] drm/i915: Track old framebuffer instead of object Daniel Vetter spotted a bug while reviewing some of my refactoring in this are of the code. I'll quote: """ > @@ -9764,6 +9768,7 @@ static int intel_crtc_page_flip(struct drm_crtc *crtc, > work->event = event; > work->crtc = crtc; > work->old_fb_obj = intel_fb_obj(old_fb); > + work->old_tiling_mode = to_intel_framebuffer(old_fb)->tiling_mode; Hm, that's actually an interesting bugfix - currently userspace could be sneaky and destroy the old fb immediately after the flip completes and the change the tiling of the underlying object before the unpin work had a chance to run (needs some fudgin with rt prios to starve workers to make this work though). Imo the right fix is to hold a reference onto the fb and not the underlying gem object. With that tiling is guaranteed not to change. """ This patch tries to implement the above proposed change. Signed-off-by: Tvrtko Ursulin Cc: Daniel Vetter Signed-off-by: Daniel Vetter --- Reading git-format-patch failed