display_bpc might not have been set before comparing with the
requested mode, so wait until afterwards before comparing with the
supported fdi bandwidth. Not a significant change as any case that
mattered would have worked; this just makes the debug messages look nicer.

Signed-off-by: Keith Packard <keithp at keithp.com>
---
 drivers/gpu/drm/i915/intel_display.c |   39 ++++++++++++++++++++--------------
 1 file changed, 23 insertions(+), 16 deletions(-)

diff --git a/drivers/gpu/drm/i915/intel_display.c 
b/drivers/gpu/drm/i915/intel_display.c
index 95248bd..b099a17 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -3804,15 +3804,6 @@ static bool intel_choose_pipe_bpp_dither(struct drm_crtc 
*crtc,
                display_bpc = 6;
        }

-       if (display_bpc * 3 > max_fdi_bpp) {
-               if (max_fdi_bpp < 24)
-                       display_bpc = 6;
-               else if (max_fdi_bpp < 30)
-                       display_bpc = 8;
-               else if (max_fdi_bpp < 36)
-                       display_bpc = 10;
-               DRM_DEBUG_KMS("Dithering FDI to %dbpc\n", display_bpc);
-       }
        /*
         * We could just drive the pipe at the highest bpc all the time and
         * enable dithering as needed, but that costs bandwidth.  So choose
@@ -3845,8 +3836,20 @@ static bool intel_choose_pipe_bpp_dither(struct drm_crtc 
*crtc,

        display_bpc = min(display_bpc, bpc);

-       DRM_DEBUG_KMS("setting pipe bpc to %d (max display bpc %d)\n",
-                     bpc, display_bpc);
+       display_bpc = 6;
+
+       if (display_bpc * 3 > max_fdi_bpp) {
+               if (max_fdi_bpp < 24)
+                       display_bpc = 6;
+               else if (max_fdi_bpp < 30)
+                       display_bpc = 8;
+               else if (max_fdi_bpp < 36)
+                       display_bpc = 10;
+               DRM_DEBUG_KMS("Dithering FDI to %dbpc\n", display_bpc);
+       }
+
+       DRM_DEBUG_KMS("setting pipe bpc to %d (max display bpc %d) (max_fdi_bpp 
%d)\n",
+                     bpc, display_bpc, max_fdi_bpp);

        *pipe_bpp = display_bpc * 3;

@@ -4737,8 +4740,7 @@ static int ironlake_crtc_mode_set(struct drm_crtc *crtc,
                max_fdi_bpp = 0;
                max_lane = lane;
        } else {
-               u32     fdi_bw;
-
+               u32 fdi_bw, pps;
                /* [e]DP over FDI requires target mode clock
                   instead of link clock */
                if (is_dp)
@@ -4763,9 +4765,12 @@ static int ironlake_crtc_mode_set(struct drm_crtc *crtc,
                 * Compute the available FDI bandwidth, use that
                 * to compute the maximum supported BPP
                 */
-               fdi_bw = link_bw * max_lane * 19 / 20;
-               max_fdi_bpp = fdi_bw / target_clock;
-               DRM_DEBUG_KMS("max lane %d yields max fdi bpp %d\n", max_lane, 
max_fdi_bpp);
+               fdi_bw = (link_bw * 8) * max_lane;
+               pps = target_clock * 21 / 20;
+
+               max_fdi_bpp = fdi_bw / pps;
+               DRM_DEBUG_KMS("link_bw %d max_lane %d fdi_bw %u pps %u 
max_fdi_bpp %d\n",
+                             link_bw, max_lane, fdi_bw, pps, max_fdi_bpp);
        }

        /* [e]DP over FDI requires target mode clock instead of link clock. */
@@ -4809,6 +4814,8 @@ static int ironlake_crtc_mode_set(struct drm_crtc *crtc,
                 */
                u32 bps = target_clock * pipe_bpp * 21 / 20;
                lane = bps / (link_bw * 8) + 1;
+               DRM_DEBUG_KMS("target_clock %u pipe_bpp %u bps %u link_bw %u 
lane %u\n",
+                             target_clock, pipe_bpp, bps, link_bw, lane);
                if (lane > max_lane) {
                        DRM_ERROR("Not enough lanes available for mode! (want 
%d have %d)\n",
                                  lane, max_lane);
-- 
1.7.10.4

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