drm/i915: don't enable FBC when pixel rate exceeds 95% on HSW/BDW

BSpec says we shouldn't enable FBC on HSW/BDW when the pipe pixel rate
exceeds 95% of the core display clock.

v2:
  - HSW also needs the WA (Ville).
  - Add the WA name (Ville).
  - Use the current cdclk (Ville).

Signed-off-by: Paulo Zanoni <paulo.r.zanoni@intel.com>
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
This commit is contained in:
Paulo Zanoni 2015-09-14 15:19:59 -03:00 committed by Daniel Vetter
parent b8bf5d7fe0
commit 7b24c9a696
2 changed files with 11 additions and 0 deletions

View File

@ -949,6 +949,7 @@ struct i915_fbc {
FBC_ROTATION, /* rotation is not supported */
FBC_IN_DBG_MASTER, /* kernel debugger is active */
FBC_BAD_STRIDE, /* stride is not supported */
FBC_PIXEL_RATE, /* pixel rate is too big */
} no_fbc_reason;
bool (*fbc_enabled)(struct drm_i915_private *dev_priv);

View File

@ -482,6 +482,8 @@ const char *intel_no_fbc_reason_str(enum no_fbc_reason reason)
return "Kernel debugger is active";
case FBC_BAD_STRIDE:
return "framebuffer stride not supported";
case FBC_PIXEL_RATE:
return "pixel rate is too big";
default:
MISSING_CASE(reason);
return "unknown reason";
@ -828,6 +830,14 @@ static void __intel_fbc_update(struct drm_i915_private *dev_priv)
goto out_disable;
}
/* WaFbcExceedCdClockThreshold:hsw,bdw */
if ((IS_HASWELL(dev_priv) || IS_BROADWELL(dev_priv)) &&
ilk_pipe_pixel_rate(intel_crtc->config) >=
dev_priv->cdclk_freq * 95 / 100) {
set_no_fbc_reason(dev_priv, FBC_PIXEL_RATE);
goto out_disable;
}
if (intel_fbc_setup_cfb(dev_priv, obj->base.size,
drm_format_plane_cpp(fb->pixel_format, 0))) {
set_no_fbc_reason(dev_priv, FBC_STOLEN_TOO_SMALL);