| Message ID | 26cddf53e9f7697fc422d19e14bfaf215d6548a6.1707823736.git.jani.nikula@intel.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | drm/i915/mst: enable MST mode for 128b/132b single-stream sideband | expand |
On Tue, Feb 13, 2024 at 01:30:57PM +0200, Jani Nikula wrote: > Rename intel_dp_can_mst() to intel_dp_mst_detect(), and move all DP MST > detect debug logging there. Debug log the sink's MST capability, > including single-stream sideband messaging support, and the decision > whether to enable MST mode or not. Do this regardless of whether we're > actually enabling MST or not. > > Cc: Arun R Murthy <arun.r.murthy@intel.com> > Cc: Ville Syrjälä <ville.syrjala@linux.intel.com> > Signed-off-by: Jani Nikula <jani.nikula@intel.com> > --- > drivers/gpu/drm/i915/display/intel_dp.c | 45 +++++++++++++++++-------- > 1 file changed, 31 insertions(+), 14 deletions(-) > > diff --git a/drivers/gpu/drm/i915/display/intel_dp.c b/drivers/gpu/drm/i915/display/intel_dp.c > index a1c304f451bd..944f566525dd 100644 > --- a/drivers/gpu/drm/i915/display/intel_dp.c > +++ b/drivers/gpu/drm/i915/display/intel_dp.c > @@ -4007,31 +4007,48 @@ intel_dp_get_dpcd(struct intel_dp *intel_dp) > intel_dp->downstream_ports) == 0; > } > > +static const char *intel_dp_mst_mode_str(enum drm_dp_mst_mode mst_mode) > +{ > + if (mst_mode == DRM_DP_SST_SIDEBAND_MSG) > + return "single-stream sideband messaging"; > + else > + return str_yes_no(mst_mode == DRM_DP_MST); I wonder if this should also just say "sst"/"mst"/"sst sideband" etc. Shrug. Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com> > +} > + > static bool > -intel_dp_can_mst(struct intel_dp *intel_dp) > +intel_dp_mst_detect(struct intel_dp *intel_dp) > { > struct drm_i915_private *i915 = dp_to_i915(intel_dp); > + struct intel_encoder *encoder = &dp_to_dig_port(intel_dp)->base; > + enum drm_dp_mst_mode sink_mst_mode; > + enum drm_dp_mst_mode mst_detect; > + > + sink_mst_mode = drm_dp_read_mst_cap(&intel_dp->aux, intel_dp->dpcd); > + > + if (i915->display.params.enable_dp_mst && > + intel_dp_mst_source_support(intel_dp) && > + sink_mst_mode == DRM_DP_MST) > + mst_detect = DRM_DP_MST; > + else > + mst_detect = DRM_DP_SST; > > - return i915->display.params.enable_dp_mst && > - intel_dp_mst_source_support(intel_dp) && > - drm_dp_read_mst_cap(&intel_dp->aux, intel_dp->dpcd) == DRM_DP_MST; > + drm_dbg_kms(&i915->drm, > + "[ENCODER:%d:%s] MST support: port: %s, sink: %s, modparam: %s -> enable: %s\n", > + encoder->base.base.id, encoder->base.name, > + str_yes_no(intel_dp_mst_source_support(intel_dp)), > + intel_dp_mst_mode_str(sink_mst_mode), > + str_yes_no(i915->display.params.enable_dp_mst), > + intel_dp_mst_mode_str(mst_detect)); > + > + return mst_detect != DRM_DP_SST; > } > > static void > intel_dp_configure_mst(struct intel_dp *intel_dp) > { > struct drm_i915_private *i915 = dp_to_i915(intel_dp); > - struct intel_encoder *encoder = > - &dp_to_dig_port(intel_dp)->base; > bool sink_can_mst = drm_dp_read_mst_cap(&intel_dp->aux, intel_dp->dpcd) == DRM_DP_MST; > > - drm_dbg_kms(&i915->drm, > - "[ENCODER:%d:%s] MST support: port: %s, sink: %s, modparam: %s\n", > - encoder->base.base.id, encoder->base.name, > - str_yes_no(intel_dp_mst_source_support(intel_dp)), > - str_yes_no(sink_can_mst), > - str_yes_no(i915->display.params.enable_dp_mst)); > - > if (!intel_dp_mst_source_support(intel_dp)) > return; > > @@ -5390,7 +5407,7 @@ intel_dp_detect_dpcd(struct intel_dp *intel_dp) > connector_status_connected : connector_status_disconnected; > } > > - if (intel_dp_can_mst(intel_dp)) > + if (intel_dp_mst_detect(intel_dp)) > return connector_status_connected; > > /* If no HPD, poke DDC gently */ > -- > 2.39.2
On Wed, 14 Feb 2024, Ville Syrjälä <ville.syrjala@linux.intel.com> wrote: > On Tue, Feb 13, 2024 at 01:30:57PM +0200, Jani Nikula wrote: >> Rename intel_dp_can_mst() to intel_dp_mst_detect(), and move all DP MST >> detect debug logging there. Debug log the sink's MST capability, >> including single-stream sideband messaging support, and the decision >> whether to enable MST mode or not. Do this regardless of whether we're >> actually enabling MST or not. >> >> Cc: Arun R Murthy <arun.r.murthy@intel.com> >> Cc: Ville Syrjälä <ville.syrjala@linux.intel.com> >> Signed-off-by: Jani Nikula <jani.nikula@intel.com> >> --- >> drivers/gpu/drm/i915/display/intel_dp.c | 45 +++++++++++++++++-------- >> 1 file changed, 31 insertions(+), 14 deletions(-) >> >> diff --git a/drivers/gpu/drm/i915/display/intel_dp.c b/drivers/gpu/drm/i915/display/intel_dp.c >> index a1c304f451bd..944f566525dd 100644 >> --- a/drivers/gpu/drm/i915/display/intel_dp.c >> +++ b/drivers/gpu/drm/i915/display/intel_dp.c >> @@ -4007,31 +4007,48 @@ intel_dp_get_dpcd(struct intel_dp *intel_dp) >> intel_dp->downstream_ports) == 0; >> } >> >> +static const char *intel_dp_mst_mode_str(enum drm_dp_mst_mode mst_mode) >> +{ >> + if (mst_mode == DRM_DP_SST_SIDEBAND_MSG) >> + return "single-stream sideband messaging"; >> + else >> + return str_yes_no(mst_mode == DRM_DP_MST); > > I wonder if this should also just say "sst"/"mst"/"sst sideband" etc. > Shrug. > > Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com> I realize there's an issue here. intel_dp_detect_dpcd() bails out early for !drm_dp_is_branch(), before the intel_dp_can_mst() call. (Renamed intel_dp_mst_detect() here.) We'll still happily call intel_dp_configure_mst() later also for !branch. We'll need to call intel_dp_mst_detect() earlier and/or somehow combine these together. I don't think branch devices need to support MST, but I think MST devices need to support branching. And single-stream sideband support does not mean branching. The intention of this patch was to improve MST debug logging, but the end result is that it reduces it! Auch. I wonder if we should branch (eh) the detect earlier for eDP, SST and MST/branch paths. Just to make it easier for our poor brains to follow. BR, Jani. > >> +} >> + >> static bool >> -intel_dp_can_mst(struct intel_dp *intel_dp) >> +intel_dp_mst_detect(struct intel_dp *intel_dp) >> { >> struct drm_i915_private *i915 = dp_to_i915(intel_dp); >> + struct intel_encoder *encoder = &dp_to_dig_port(intel_dp)->base; >> + enum drm_dp_mst_mode sink_mst_mode; >> + enum drm_dp_mst_mode mst_detect; >> + >> + sink_mst_mode = drm_dp_read_mst_cap(&intel_dp->aux, intel_dp->dpcd); >> + >> + if (i915->display.params.enable_dp_mst && >> + intel_dp_mst_source_support(intel_dp) && >> + sink_mst_mode == DRM_DP_MST) >> + mst_detect = DRM_DP_MST; >> + else >> + mst_detect = DRM_DP_SST; >> >> - return i915->display.params.enable_dp_mst && >> - intel_dp_mst_source_support(intel_dp) && >> - drm_dp_read_mst_cap(&intel_dp->aux, intel_dp->dpcd) == DRM_DP_MST; >> + drm_dbg_kms(&i915->drm, >> + "[ENCODER:%d:%s] MST support: port: %s, sink: %s, modparam: %s -> enable: %s\n", >> + encoder->base.base.id, encoder->base.name, >> + str_yes_no(intel_dp_mst_source_support(intel_dp)), >> + intel_dp_mst_mode_str(sink_mst_mode), >> + str_yes_no(i915->display.params.enable_dp_mst), >> + intel_dp_mst_mode_str(mst_detect)); >> + >> + return mst_detect != DRM_DP_SST; >> } >> >> static void >> intel_dp_configure_mst(struct intel_dp *intel_dp) >> { >> struct drm_i915_private *i915 = dp_to_i915(intel_dp); >> - struct intel_encoder *encoder = >> - &dp_to_dig_port(intel_dp)->base; >> bool sink_can_mst = drm_dp_read_mst_cap(&intel_dp->aux, intel_dp->dpcd) == DRM_DP_MST; >> >> - drm_dbg_kms(&i915->drm, >> - "[ENCODER:%d:%s] MST support: port: %s, sink: %s, modparam: %s\n", >> - encoder->base.base.id, encoder->base.name, >> - str_yes_no(intel_dp_mst_source_support(intel_dp)), >> - str_yes_no(sink_can_mst), >> - str_yes_no(i915->display.params.enable_dp_mst)); >> - >> if (!intel_dp_mst_source_support(intel_dp)) >> return; >> >> @@ -5390,7 +5407,7 @@ intel_dp_detect_dpcd(struct intel_dp *intel_dp) >> connector_status_connected : connector_status_disconnected; >> } >> >> - if (intel_dp_can_mst(intel_dp)) >> + if (intel_dp_mst_detect(intel_dp)) >> return connector_status_connected; >> >> /* If no HPD, poke DDC gently */ >> -- >> 2.39.2
On Thu, Feb 15, 2024 at 01:46:48PM +0200, Jani Nikula wrote: > On Wed, 14 Feb 2024, Ville Syrjälä <ville.syrjala@linux.intel.com> wrote: > > On Tue, Feb 13, 2024 at 01:30:57PM +0200, Jani Nikula wrote: > >> Rename intel_dp_can_mst() to intel_dp_mst_detect(), and move all DP MST > >> detect debug logging there. Debug log the sink's MST capability, > >> including single-stream sideband messaging support, and the decision > >> whether to enable MST mode or not. Do this regardless of whether we're > >> actually enabling MST or not. > >> > >> Cc: Arun R Murthy <arun.r.murthy@intel.com> > >> Cc: Ville Syrjälä <ville.syrjala@linux.intel.com> > >> Signed-off-by: Jani Nikula <jani.nikula@intel.com> > >> --- > >> drivers/gpu/drm/i915/display/intel_dp.c | 45 +++++++++++++++++-------- > >> 1 file changed, 31 insertions(+), 14 deletions(-) > >> > >> diff --git a/drivers/gpu/drm/i915/display/intel_dp.c b/drivers/gpu/drm/i915/display/intel_dp.c > >> index a1c304f451bd..944f566525dd 100644 > >> --- a/drivers/gpu/drm/i915/display/intel_dp.c > >> +++ b/drivers/gpu/drm/i915/display/intel_dp.c > >> @@ -4007,31 +4007,48 @@ intel_dp_get_dpcd(struct intel_dp *intel_dp) > >> intel_dp->downstream_ports) == 0; > >> } > >> > >> +static const char *intel_dp_mst_mode_str(enum drm_dp_mst_mode mst_mode) > >> +{ > >> + if (mst_mode == DRM_DP_SST_SIDEBAND_MSG) > >> + return "single-stream sideband messaging"; > >> + else > >> + return str_yes_no(mst_mode == DRM_DP_MST); > > > > I wonder if this should also just say "sst"/"mst"/"sst sideband" etc. > > Shrug. > > > > Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com> > > I realize there's an issue here. > > intel_dp_detect_dpcd() bails out early for !drm_dp_is_branch(), before > the intel_dp_can_mst() call. (Renamed intel_dp_mst_detect() here.) > > We'll still happily call intel_dp_configure_mst() later also for > !branch. > > We'll need to call intel_dp_mst_detect() earlier and/or somehow combine > these together. I don't think branch devices need to support MST, but I > think MST devices need to support branching. And single-stream sideband > support does not mean branching. > > The intention of this patch was to improve MST debug logging, but the > end result is that it reduces it! Auch. > > I wonder if we should branch (eh) the detect earlier for eDP, SST and > MST/branch paths. Just to make it easier for our poor brains to follow. Hmm. The sink count check is another case as well. If the device has a local sink, or somehting connected to its DFP(s) it should declare sink count >= 1.
diff --git a/drivers/gpu/drm/i915/display/intel_dp.c b/drivers/gpu/drm/i915/display/intel_dp.c index a1c304f451bd..944f566525dd 100644 --- a/drivers/gpu/drm/i915/display/intel_dp.c +++ b/drivers/gpu/drm/i915/display/intel_dp.c @@ -4007,31 +4007,48 @@ intel_dp_get_dpcd(struct intel_dp *intel_dp) intel_dp->downstream_ports) == 0; } +static const char *intel_dp_mst_mode_str(enum drm_dp_mst_mode mst_mode) +{ + if (mst_mode == DRM_DP_SST_SIDEBAND_MSG) + return "single-stream sideband messaging"; + else + return str_yes_no(mst_mode == DRM_DP_MST); +} + static bool -intel_dp_can_mst(struct intel_dp *intel_dp) +intel_dp_mst_detect(struct intel_dp *intel_dp) { struct drm_i915_private *i915 = dp_to_i915(intel_dp); + struct intel_encoder *encoder = &dp_to_dig_port(intel_dp)->base; + enum drm_dp_mst_mode sink_mst_mode; + enum drm_dp_mst_mode mst_detect; + + sink_mst_mode = drm_dp_read_mst_cap(&intel_dp->aux, intel_dp->dpcd); + + if (i915->display.params.enable_dp_mst && + intel_dp_mst_source_support(intel_dp) && + sink_mst_mode == DRM_DP_MST) + mst_detect = DRM_DP_MST; + else + mst_detect = DRM_DP_SST; - return i915->display.params.enable_dp_mst && - intel_dp_mst_source_support(intel_dp) && - drm_dp_read_mst_cap(&intel_dp->aux, intel_dp->dpcd) == DRM_DP_MST; + drm_dbg_kms(&i915->drm, + "[ENCODER:%d:%s] MST support: port: %s, sink: %s, modparam: %s -> enable: %s\n", + encoder->base.base.id, encoder->base.name, + str_yes_no(intel_dp_mst_source_support(intel_dp)), + intel_dp_mst_mode_str(sink_mst_mode), + str_yes_no(i915->display.params.enable_dp_mst), + intel_dp_mst_mode_str(mst_detect)); + + return mst_detect != DRM_DP_SST; } static void intel_dp_configure_mst(struct intel_dp *intel_dp) { struct drm_i915_private *i915 = dp_to_i915(intel_dp); - struct intel_encoder *encoder = - &dp_to_dig_port(intel_dp)->base; bool sink_can_mst = drm_dp_read_mst_cap(&intel_dp->aux, intel_dp->dpcd) == DRM_DP_MST; - drm_dbg_kms(&i915->drm, - "[ENCODER:%d:%s] MST support: port: %s, sink: %s, modparam: %s\n", - encoder->base.base.id, encoder->base.name, - str_yes_no(intel_dp_mst_source_support(intel_dp)), - str_yes_no(sink_can_mst), - str_yes_no(i915->display.params.enable_dp_mst)); - if (!intel_dp_mst_source_support(intel_dp)) return; @@ -5390,7 +5407,7 @@ intel_dp_detect_dpcd(struct intel_dp *intel_dp) connector_status_connected : connector_status_disconnected; } - if (intel_dp_can_mst(intel_dp)) + if (intel_dp_mst_detect(intel_dp)) return connector_status_connected; /* If no HPD, poke DDC gently */
Rename intel_dp_can_mst() to intel_dp_mst_detect(), and move all DP MST detect debug logging there. Debug log the sink's MST capability, including single-stream sideband messaging support, and the decision whether to enable MST mode or not. Do this regardless of whether we're actually enabling MST or not. Cc: Arun R Murthy <arun.r.murthy@intel.com> Cc: Ville Syrjälä <ville.syrjala@linux.intel.com> Signed-off-by: Jani Nikula <jani.nikula@intel.com> --- drivers/gpu/drm/i915/display/intel_dp.c | 45 +++++++++++++++++-------- 1 file changed, 31 insertions(+), 14 deletions(-)