[Intel-gfx] [PATCH igt 2/3] kms_frontbuffer_tracking: recreate the FBs at every subtest

[Paulo Zanoni]

This patch was originally written because of a workaround we were
planning to merge. Later we improved the workaround so it wouldn't
need this patch anymore. Then later we gave up on the workaround, but
decided to go with a plan that would cause GTT mmap writes to
invalidate FBC in case the frontbuffer ever had a WC mmap. So now we
need the patch again because we don't want a subtest that involves an
WC mmap to change the behavior of other unrelated subtests that use
GTT mmaps.

Even if we don't go with the current planned Kernel patch, merging
this should be worth in order to avoid future related problems.

v2: New commit message.

Signed-off-by: Paulo Zanoni <paulo.r.zanoni at intel.com>
---
 tests/kms_frontbuffer_tracking.c | 40 ++++++++++++++++++++--------------------
 1 file changed, 20 insertions(+), 20 deletions(-)

diff --git a/tests/kms_frontbuffer_tracking.c b/tests/kms_frontbuffer_tracking.c
index c6d6bc0..f37de6d 100644
--- a/tests/kms_frontbuffer_tracking.c
+++ b/tests/kms_frontbuffer_tracking.c
@@ -711,12 +711,31 @@ static void create_shared_fb(enum pixel_format format)
 		  PLANE_PRI, &s->big);
 }
 
+static void destroy_fbs(enum pixel_format format)
+{
+	struct screen_fbs *s = &fbs[format];
+
+	if (!s->initialized)
+		return;
+
+	if (scnd_mode_params.connector_id) {
+		igt_remove_fb(drm.fd, &s->scnd_pri);
+		igt_remove_fb(drm.fd, &s->scnd_cur);
+		igt_remove_fb(drm.fd, &s->scnd_spr);
+	}
+	igt_remove_fb(drm.fd, &s->prim_pri);
+	igt_remove_fb(drm.fd, &s->prim_cur);
+	igt_remove_fb(drm.fd, &s->prim_spr);
+	igt_remove_fb(drm.fd, &s->offscreen);
+	igt_remove_fb(drm.fd, &s->big);
+}
+
 static void create_fbs(enum pixel_format format)
 {
 	struct screen_fbs *s = &fbs[format];
 
 	if (s->initialized)
-		return;
+		destroy_fbs(format);
 
 	s->initialized = true;
 
@@ -747,25 +766,6 @@ static void create_fbs(enum pixel_format format)
 		  LOCAL_I915_FORMAT_MOD_X_TILED, PLANE_SPR, &s->scnd_spr);
 }
 
-static void destroy_fbs(enum pixel_format format)
-{
-	struct screen_fbs *s = &fbs[format];
-
-	if (!s->initialized)
-		return;
-
-	if (scnd_mode_params.connector_id) {
-		igt_remove_fb(drm.fd, &s->scnd_pri);
-		igt_remove_fb(drm.fd, &s->scnd_cur);
-		igt_remove_fb(drm.fd, &s->scnd_spr);
-	}
-	igt_remove_fb(drm.fd, &s->prim_pri);
-	igt_remove_fb(drm.fd, &s->prim_cur);
-	igt_remove_fb(drm.fd, &s->prim_spr);
-	igt_remove_fb(drm.fd, &s->offscreen);
-	igt_remove_fb(drm.fd, &s->big);
-}
-
 static bool set_mode_for_params(struct modeset_params *params)
 {
 	int rc;
-- 
2.8.0.rc3