<html> <head> <base href="https://bugs.freedesktop.org/" /> </head> <body> <div> <a class="bz_bug_link bz_status_NEEDINFO " title="NEEDINFO --- - [915 Haswell ULT Asus UX302LA/LG] eDP bpp clamping results in blank screen" href="https://bugs.freedesktop.org/show_bug.cgi?id=73567#c15">Comment # 15</a> on <a class="bz_bug_link bz_status_NEEDINFO " title="NEEDINFO --- - [915 Haswell ULT Asus UX302LA/LG] eDP bpp clamping results in blank screen" href="https://bugs.freedesktop.org/show_bug.cgi?id=73567">bug 73567</a> from <a class="email" href="mailto:jani.nikula@intel.com" title="Jani Nikula <jani.nikula@intel.com>"> Jani Nikula</a> <pre>(In reply to <a href="show_bug.cgi?id=73567#c13">comment #13</a>) > Daniel, > > I'm already running drm-intel-nightly which includes that commit. > That particular hack does indeed run (see attached dmesg log at the > beginning) but the panel is still blank. I saw the same hack at > intel_dp_get_config, but in my machine intel_dp_get_config does not get > called at all. > > The culprit is clamping bpp from 24 to 18 bpp at intel_dp_compute_config. > When the bpp clamping code is disabled and the panel runs at 24 bpp there > are no more blank screen issues. Please try this on drm-intel-nightly, and report what the debug says: diff --git a/drivers/gpu/drm/i915/intel_ddi.c b/drivers/gpu/drm/i915/intel_ddi.c index 74749c6..dbc5a16 100644 --- a/drivers/gpu/drm/i915/intel_ddi.c +++ b/drivers/gpu/drm/i915/intel_ddi.c @@ -1491,6 +1491,10 @@ void intel_ddi_get_config(struct intel_encoder *encoder, break; } + DRM_DEBUG_KMS("encoder type %d, pipe_bpp %d, vbt.edp_bpp %d, ddi ctl %08x\n", + encoder->type, pipe_config->pipe_bpp, + dev_priv->vbt.edp_bpp, temp); + if (encoder->type == INTEL_OUTPUT_EDP && dev_priv->vbt.edp_bpp && pipe_config->pipe_bpp > dev_priv->vbt.edp_bpp) { /*</pre> </div> <hr> You are receiving this mail because: <ul> <li>You are the QA Contact for the bug.</li> <li>You are on the CC list for the bug.</li> <li>You are the assignee for the bug.</li> </ul> </body> </html>