| Message ID | 20181003184210.1306-1-ville.syrjala@linux.intel.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | drm/i915: Provide more clues as to why MST is/is not used | expand |
On Wednesday, October 3, 2018 11:42:10 AM PDT Ville Syrjala wrote: > From: Ville Syrjälä <ville.syrjala@linux.intel.com> > > Always print out the information whether the port and sink can each > do MST. And let's include the modparam in the debug output as well. > Makes life a little less confusing when you don't have to wonder > why MST isn't kicking in. > > This does cause a slight change in our behaviour towards the sink. > Previously we only read the MSTM_CAP register after passing all > the other checks. Now we will read that register regardless. Hopefully > some crazy sink doesn't get confused by a simple register read. > > Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com> > --- > drivers/gpu/drm/i915/intel_dp.c | 33 ++++++++++++++++++--------------- > 1 file changed, 18 insertions(+), 15 deletions(-) > > diff --git a/drivers/gpu/drm/i915/intel_dp.c > b/drivers/gpu/drm/i915/intel_dp.c index 15a981ef5966..1a510cf58fb5 100644 > --- a/drivers/gpu/drm/i915/intel_dp.c > +++ b/drivers/gpu/drm/i915/intel_dp.c > @@ -4050,16 +4050,10 @@ intel_dp_get_dpcd(struct intel_dp *intel_dp) > } > > static bool > -intel_dp_can_mst(struct intel_dp *intel_dp) > +intel_dp_sink_can_mst(struct intel_dp *intel_dp) > { > u8 mstm_cap; > > - if (!i915_modparams.enable_dp_mst) > - return false; > - > - if (!intel_dp->can_mst) > - return false; > - > if (intel_dp->dpcd[DP_DPCD_REV] < 0x12) > return false; > > @@ -4069,21 +4063,30 @@ intel_dp_can_mst(struct intel_dp *intel_dp) > return mstm_cap & DP_MST_CAP; > } > > +static bool > +intel_dp_can_mst(struct intel_dp *intel_dp) > +{ > + return i915_modparams.enable_dp_mst && > + intel_dp->can_mst && > + intel_dp_sink_can_mst(intel_dp); > +} > + > static void > intel_dp_configure_mst(struct intel_dp *intel_dp) > { > - if (!i915_modparams.enable_dp_mst) > - return; > + struct intel_encoder *encoder = > + &dp_to_dig_port(intel_dp)->base; > + bool sink_can_mst = intel_dp_sink_can_mst(intel_dp); > + > + DRM_DEBUG_KMS("MST support? port %c: %s, sink: %s, modparam: %s\n", > + port_name(encoder->port), yesno(intel_dp->can_mst), > + yesno(sink_can_mst), yesno(i915_modparams.enable_dp_mst)); > > if (!intel_dp->can_mst) > return; > > - intel_dp->is_mst = intel_dp_can_mst(intel_dp); > - > - if (intel_dp->is_mst) > - DRM_DEBUG_KMS("Sink is MST capable\n"); > - else > - DRM_DEBUG_KMS("Sink is not MST capable\n"); > + intel_dp->is_mst = sink_can_mst && > + i915_modparams.enable_dp_mst; Should we still keep this modparam around? I don't know if anyone actually uses it to work around MST issues. Even if there are MST issues, we should be fixing them. I see the value in the debug message, Reviewed-by: Dhinakaran Pandiyan <dhinakaran.pandiyan@intel.com> > > drm_dp_mst_topology_mgr_set_mst(&intel_dp->mst_mgr, > intel_dp->is_mst);
diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c index 15a981ef5966..1a510cf58fb5 100644 --- a/drivers/gpu/drm/i915/intel_dp.c +++ b/drivers/gpu/drm/i915/intel_dp.c @@ -4050,16 +4050,10 @@ intel_dp_get_dpcd(struct intel_dp *intel_dp) } static bool -intel_dp_can_mst(struct intel_dp *intel_dp) +intel_dp_sink_can_mst(struct intel_dp *intel_dp) { u8 mstm_cap; - if (!i915_modparams.enable_dp_mst) - return false; - - if (!intel_dp->can_mst) - return false; - if (intel_dp->dpcd[DP_DPCD_REV] < 0x12) return false; @@ -4069,21 +4063,30 @@ intel_dp_can_mst(struct intel_dp *intel_dp) return mstm_cap & DP_MST_CAP; } +static bool +intel_dp_can_mst(struct intel_dp *intel_dp) +{ + return i915_modparams.enable_dp_mst && + intel_dp->can_mst && + intel_dp_sink_can_mst(intel_dp); +} + static void intel_dp_configure_mst(struct intel_dp *intel_dp) { - if (!i915_modparams.enable_dp_mst) - return; + struct intel_encoder *encoder = + &dp_to_dig_port(intel_dp)->base; + bool sink_can_mst = intel_dp_sink_can_mst(intel_dp); + + DRM_DEBUG_KMS("MST support? port %c: %s, sink: %s, modparam: %s\n", + port_name(encoder->port), yesno(intel_dp->can_mst), + yesno(sink_can_mst), yesno(i915_modparams.enable_dp_mst)); if (!intel_dp->can_mst) return; - intel_dp->is_mst = intel_dp_can_mst(intel_dp); - - if (intel_dp->is_mst) - DRM_DEBUG_KMS("Sink is MST capable\n"); - else - DRM_DEBUG_KMS("Sink is not MST capable\n"); + intel_dp->is_mst = sink_can_mst && + i915_modparams.enable_dp_mst; drm_dp_mst_topology_mgr_set_mst(&intel_dp->mst_mgr, intel_dp->is_mst);