drm/i915: Disable FBC WM on ILK, and disable LP2+ when FBC is enabled
ILK has a bunch of issues with FBC. First of all, BSpec tells us that
FBC WM should never be enabled. Secondly when FBC is enabled
with FBC WM disabled, LP2+ watermarks must be disabled.
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: Imre Deak <imre.deak@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
diff --git a/drivers/gpu/drm/i915/intel_pm.c b/drivers/gpu/drm/i915/intel_pm.c
index a65d881..3d4daa1 100644
--- a/drivers/gpu/drm/i915/intel_pm.c
+++ b/drivers/gpu/drm/i915/intel_pm.c
@@ -2701,7 +2701,8 @@
config->num_pipes_active > 1)
return;
- merged->fbc_wm_enabled = true;
+ /* ILK: FBC WM must be disabled always */
+ merged->fbc_wm_enabled = INTEL_INFO(dev)->gen >= 6;
/* merge each WM1+ level */
for (level = 1; level <= max_level; level++) {
@@ -2721,6 +2722,20 @@
wm->fbc_val = 0;
}
}
+
+ /* ILK: LP2+ must be disabled when FBC WM is disabled but FBC enabled */
+ /*
+ * FIXME this is racy. FBC might get enabled later.
+ * What we should check here is whether FBC can be
+ * enabled sometime later.
+ */
+ if (IS_GEN5(dev) && !merged->fbc_wm_enabled && intel_fbc_enabled(dev)) {
+ for (level = 2; level <= max_level; level++) {
+ struct intel_wm_level *wm = &merged->wm[level];
+
+ wm->enable = false;
+ }
+ }
}
static int ilk_wm_lp_to_level(int wm_lp, const struct intel_pipe_wm *pipe_wm)