Revert "drm/i915: revert eDP bpp clamping code changes"

This reverts commit 57c219633275c7e7413f8bc7be250dc092887458.

It's an ugly hack for a Haswell SDV platform where the vbt doesn't
seem to fully agree with the panel. Since it seems to cause issues on
real eDP platform let's just kill this hack again.

Reported-and-tested-by: Josh Boyer <jwboyer@gmail.com>
References: https://lkml.org/lkml/2013/5/3/467
Cc: Paulo Zanoni <przanoni@gmail.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c
index fc3bd9b4037c61409da87c3d45a9ad89b261a3a9..0ab9813a79b5fd913a363d8b614e4d5aee3b5864 100644 (file)
--- a/drivers/gpu/drm/i915/intel_dp.c
+++ b/drivers/gpu/drm/i915/intel_dp.c
@@ -702,6 +702,9 @@ intel_dp_compute_config(struct intel_encoder *encoder,
        /* Walk through all bpp values. Luckily they're all nicely spaced with 2
         * bpc in between. */
        bpp = min_t(int, 8*3, pipe_config->pipe_bpp);
+       if (is_edp(intel_dp) && dev_priv->edp.bpp)
+               bpp = min_t(int, bpp, dev_priv->edp.bpp);
+
        for (; bpp >= 6*3; bpp -= 2*3) {
                mode_rate = intel_dp_link_required(target_clock, bpp);
 
@@ -739,6 +742,7 @@ found:
        intel_dp->link_bw = bws[clock];
        intel_dp->lane_count = lane_count;
        adjusted_mode->clock = drm_dp_bw_code_to_link_rate(intel_dp->link_bw);
+       pipe_config->pipe_bpp = bpp;
        pipe_config->pixel_target_clock = target_clock;
 
        DRM_DEBUG_KMS("DP link bw %02x lane count %d clock %d bpp %d\n",
@@ -751,20 +755,6 @@ found:
                               target_clock, adjusted_mode->clock,
                               &pipe_config->dp_m_n);
 
-       /*
-        * XXX: We have a strange regression where using the vbt edp bpp value
-        * for the link bw computation results in black screens, the panel only
-        * works when we do the computation at the usual 24bpp (but still
-        * requires us to use 18bpp). Until that's fully debugged, stay
-        * bug-for-bug compatible with the old code.
-        */
-       if (is_edp(intel_dp) && dev_priv->edp.bpp) {
-               DRM_DEBUG_KMS("clamping display bpc (was %d) to eDP (%d)\n",
-                             bpp, dev_priv->edp.bpp);
-               bpp = min_t(int, bpp, dev_priv->edp.bpp);
-       }
-       pipe_config->pipe_bpp = bpp;
-
        return true;
 }