drm/i915: Warn if we run out of FIFO space for a mode
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Jesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: Eric Anholt <eric@anholt.net>
diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index baaaeaa..132314e 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -2745,8 +2745,14 @@
/* Don't promote wm_size to unsigned... */
if (wm_size > (long)wm->max_wm)
wm_size = wm->max_wm;
- if (wm_size <= 0)
+ if (wm_size <= 0) {
wm_size = wm->default_wm;
+ DRM_ERROR("Insufficient FIFO for plane, expect flickering:"
+ " entries required = %ld, available = %lu.\n",
+ entries_required + wm->guard_size,
+ wm->fifo_size);
+ }
+
return wm_size;
}