On Fri, 02 Feb 2024, Ville Syrjälä <ville.syrjala@xxxxxxxxxxxxxxx> wrote:
> On Fri, Feb 02, 2024 at 04:05:32PM +0200, Jani Nikula wrote:
>> Currently we've split MST capability detection in two places,
>> intel_dp_can_mst() and intel_dp_configure_mst(). They check essentially
>> the same things.
>>
>> Move bulk of the work, including logging, to intel_dp_can_mst() and
>> rename it intel_dp_mst_detect(). Set intel_dp->is_mst there to avoid
>> duplicate work.
>
> This seems confusing. is_mst is supposed to reflect the state
> of the topology manager, nothing more.
We'll, that's still exactly what we're going to set the topology manager
state to. It's just that now we figure it out just a little earlier, so
we don't have to duplicate the dpcd reads and logic to two places.
BR,
Jani.
>
>>
>> Rename intel_dp_configure_mst() to intel_dp_mst_configure(), and only
>> set the topology manager state there.
>>
>> The main functional difference is that the DP_MSTM_CAP DPCD register is
>> now only read once at detect, unconditionally, and the MST support is
>> always logged. Everything else should remain the same.
>>
>> Cc: Arun R Murthy <arun.r.murthy@xxxxxxxxx>
>> Cc: Ville Syrjälä <ville.syrjala@xxxxxxxxxxxxxxx>
>> Signed-off-by: Jani Nikula <jani.nikula@xxxxxxxxx>
>> ---
>> drivers/gpu/drm/i915/display/intel_dp.c | 36 ++++++++++---------------
>> 1 file changed, 14 insertions(+), 22 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/i915/display/intel_dp.c b/drivers/gpu/drm/i915/display/intel_dp.c
>> index 7af09f2c008d..e0b8ee6bde79 100644
>> --- a/drivers/gpu/drm/i915/display/intel_dp.c
>> +++ b/drivers/gpu/drm/i915/display/intel_dp.c
>> @@ -4004,23 +4004,15 @@ intel_dp_get_dpcd(struct intel_dp *intel_dp)
>> intel_dp->downstream_ports) == 0;
>> }
>>
>> -static bool
>> -intel_dp_can_mst(struct intel_dp *intel_dp)
>> +static bool 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;
>> + bool sink_can_mst = drm_dp_read_mst_cap(&intel_dp->aux, intel_dp->dpcd) == DP_MST_CAPABLE;
>>
>> - return i915->display.params.enable_dp_mst &&
>> + intel_dp->is_mst = i915->display.params.enable_dp_mst &&
>> intel_dp_mst_source_support(intel_dp) &&
>> - drm_dp_read_mst_cap(&intel_dp->aux, intel_dp->dpcd) == DP_MST_CAPABLE;
>> -}
>> -
>> -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) == DP_MST_CAPABLE;
>> + sink_can_mst;
>>
>> drm_dbg_kms(&i915->drm,
>> "[ENCODER:%d:%s] MST support: port: %s, sink: %s, modparam: %s\n",
>> @@ -4029,14 +4021,14 @@ intel_dp_configure_mst(struct intel_dp *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;
>> -
>> - intel_dp->is_mst = sink_can_mst &&
>> - i915->display.params.enable_dp_mst;
>> + return intel_dp->is_mst;
>> +}
>>
>> - drm_dp_mst_topology_mgr_set_mst(&intel_dp->mst_mgr,
>> - intel_dp->is_mst);
>> +static void intel_dp_mst_configure(struct intel_dp *intel_dp)
>> +{
>> + if (intel_dp_mst_source_support(intel_dp))
>> + drm_dp_mst_topology_mgr_set_mst(&intel_dp->mst_mgr,
>> + intel_dp->is_mst);
>> }
>>
>> static bool
>> @@ -5387,7 +5379,7 @@ 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 */
>> @@ -5706,7 +5698,7 @@ intel_dp_detect(struct drm_connector *connector,
>>
>> intel_dp_detect_dsc_caps(intel_dp, intel_connector);
>>
>> - intel_dp_configure_mst(intel_dp);
>> + intel_dp_mst_configure(intel_dp);
>>
>> /*
>> * TODO: Reset link params when switching to MST mode, until MST
>> --
>> 2.39.2
--
Jani Nikula, Intel
