drm/i915: read bpp from vbt only for older panels

BPP bits defined in VBT should be used only on panels whose
edid version is 1.3 or older. EDID version 1.4 introduced offsets
where bpp is defined and read into display_info, hence bpp from
VBT will be used only when bpc in display_info is zero.

v2: use display_info.bpc for deciding when to use vbt_bpp (Jani)

Signed-off-by: Sivakumar Thulasimani <sivakumar.thulasimani@intel.com>
Reviewed-by: Jani Nikula <jani.nikula@intel.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 10cbc9879e00ea6496a1f34facc96d5330905796..df7e2cfef38dfbc7ccee0d0d4123b2c94b60d9a1 100644 (file)
--- a/drivers/gpu/drm/i915/intel_dp.c
+++ b/drivers/gpu/drm/i915/intel_dp.c
@@ -1409,7 +1409,10 @@ intel_dp_compute_config(struct intel_encoder *encoder,
         * bpc in between. */
        bpp = pipe_config->pipe_bpp;
        if (is_edp(intel_dp)) {
-               if (dev_priv->vbt.edp_bpp && dev_priv->vbt.edp_bpp < bpp) {
+
+               /* Get bpp from vbt only for panels that dont have bpp in edid */
+               if (intel_connector->base.display_info.bpc == 0 &&
+                       (dev_priv->vbt.edp_bpp && dev_priv->vbt.edp_bpp < bpp)) {
                        DRM_DEBUG_KMS("clamping bpp for eDP panel to BIOS-provided %i\n",
                                      dev_priv->vbt.edp_bpp);
                        bpp = dev_priv->vbt.edp_bpp;