drm/i915/skl+: Use scaling amount for plane data rate calculation (v4)
authorKumar, Mahesh <mahesh1.kumar@intel.com>
Thu, 19 May 2016 22:03:01 +0000 (15:03 -0700)
committerMatt Roper <matthew.d.roper@intel.com>
Wed, 1 Jun 2016 14:37:39 +0000 (07:37 -0700)
if downscaling is enabled plane data rate increases according to scaling
amount. take scaling amount under consideration while calculating plane
data rate

v2: Address Matt's comments, where data rate was overridden because of
missing else.

v3 (by Matt):
 - Add braces to 'else' branch to match kernel coding style
 - Adjust final calculation now that skl_plane_downscale_amount()
   returns 16.16 fixed point value instead of a decimal fixed point

v4 (by Matt):
 - Avoid integer overflow by making sure final multiplication is
   treated as 64-bit.

Cc: matthew.d.roper@intel.com
Signed-off-by: Kumar, Mahesh <mahesh1.kumar@intel.com>
Signed-off-by: Matt Roper <matthew.d.roper@intel.com>
Reviewed-by: Kumar Mahesh <mahesh1.kumar@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1463695381-21368-1-git-send-email-matthew.d.roper@intel.com
drivers/gpu/drm/i915/intel_pm.c

index ceb1eecd9dadd8ec68e25c50030e53f63ed1369b..08274591db7eb5f93b6df2bf7f9c58f816067c01 100644 (file)
@@ -2997,6 +2997,7 @@ skl_plane_relative_data_rate(const struct intel_crtc_state *cstate,
 {
        struct intel_plane_state *intel_pstate = to_intel_plane_state(pstate);
        struct drm_framebuffer *fb = pstate->fb;
+       uint32_t down_scale_amount, data_rate;
        uint32_t width = 0, height = 0;
        unsigned format = fb ? fb->pixel_format : DRM_FORMAT_XRGB8888;
 
@@ -3016,15 +3017,19 @@ skl_plane_relative_data_rate(const struct intel_crtc_state *cstate,
        /* for planar format */
        if (format == DRM_FORMAT_NV12) {
                if (y)  /* y-plane data rate */
-                       return width * height *
+                       data_rate = width * height *
                                drm_format_plane_cpp(format, 0);
                else    /* uv-plane data rate */
-                       return (width / 2) * (height / 2) *
+                       data_rate = (width / 2) * (height / 2) *
                                drm_format_plane_cpp(format, 1);
+       } else {
+               /* for packed formats */
+               data_rate = width * height * drm_format_plane_cpp(format, 0);
        }
 
-       /* for packed formats */
-       return width * height * drm_format_plane_cpp(format, 0);
+       down_scale_amount = skl_plane_downscale_amount(intel_pstate);
+
+       return (uint64_t)data_rate * down_scale_amount >> 16;
 }
 
 /*