On Tue, Aug 14, 2012 at 5:34 AM, Keith Packard <keithp at keithp.com> wrote:
> @@ -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;
It seems that you are overriding display_bpc unconditionally here,
some left over from debugging?
> + 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;
"setting pipe bpc to %d", bpc and *pipe_bpp = display_bpc, looks like
a bogus debug message to me.
> @@ -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);
> }
While I understood the first computation of max_fdi_bpp in patch 2 of
this series, I have to confess you lost me there. Would you mind
clarifying this?
--
Damien
