[PATCH v2 06/16] drm/i915/mst: split out a helper for figuring out the TU
Jani Nikula
jani.nikula at intel.com
Thu Jan 2 10:19:09 UTC 2025
On Tue, 31 Dec 2024, Imre Deak <imre.deak at intel.com> wrote:
> On Thu, Dec 19, 2024 at 11:33:55PM +0200, Jani Nikula wrote:
>> Extract intel_dp_mtp_tu_compute_config() for figuring out the TU. Move
>> the link configuration and mst state access to the callers. This will be
>> easier to adapt to 128b/132b SST.
>>
>> v2: Don't add SST stuff here yet
>>
>> Signed-off-by: Jani Nikula <jani.nikula at intel.com>
>> ---
>> drivers/gpu/drm/i915/display/intel_dp_mst.c | 53 ++++++++++++++-------
>> drivers/gpu/drm/i915/display/intel_dp_mst.h | 7 +++
>> 2 files changed, 42 insertions(+), 18 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/i915/display/intel_dp_mst.c b/drivers/gpu/drm/i915/display/intel_dp_mst.c
>> index 51f0248084b6..d08824d2fefe 100644
>> --- a/drivers/gpu/drm/i915/display/intel_dp_mst.c
>> +++ b/drivers/gpu/drm/i915/display/intel_dp_mst.c
>> @@ -209,31 +209,23 @@ static int intel_dp_mst_dsc_get_slice_count(const struct intel_connector *connec
>> num_joined_pipes);
>> }
>>
>> -static int mst_stream_find_vcpi_slots_for_bpp(struct intel_dp *intel_dp,
>> - struct intel_crtc_state *crtc_state,
>> - int max_bpp, int min_bpp,
>> - struct link_config_limits *limits,
>> - struct drm_connector_state *conn_state,
>> - int step, bool dsc)
>> +int intel_dp_mtp_tu_compute_config(struct intel_dp *intel_dp,
>> + struct intel_crtc_state *crtc_state,
>> + int max_bpp, int min_bpp,
>> + struct drm_connector_state *conn_state,
>> + int step, bool dsc)
>> {
>> struct intel_display *display = to_intel_display(intel_dp);
>> struct drm_atomic_state *state = crtc_state->uapi.state;
>> - struct drm_dp_mst_topology_state *mst_state;
>> struct intel_connector *connector =
>> to_intel_connector(conn_state->connector);
>> const struct drm_display_mode *adjusted_mode =
>> &crtc_state->hw.adjusted_mode;
>> + fixed20_12 pbn_div;
>> int bpp, slots = -EINVAL;
>> int dsc_slice_count = 0;
>> int max_dpt_bpp;
>>
>> - mst_state = drm_atomic_get_mst_topology_state(state, &intel_dp->mst_mgr);
>> - if (IS_ERR(mst_state))
>> - return PTR_ERR(mst_state);
>> -
>> - crtc_state->lane_count = limits->max_lane_count;
>> - crtc_state->port_clock = limits->max_rate;
>> -
>> if (dsc) {
>> if (!intel_dp_supports_fec(intel_dp, connector, crtc_state))
>> return -EINVAL;
>> @@ -241,8 +233,8 @@ static int mst_stream_find_vcpi_slots_for_bpp(struct intel_dp *intel_dp,
>> crtc_state->fec_enable = !intel_dp_is_uhbr(crtc_state);
>> }
>>
>> - mst_state->pbn_div = drm_dp_get_vc_payload_bw(crtc_state->port_clock,
>> - crtc_state->lane_count);
>> + pbn_div = drm_dp_get_vc_payload_bw(crtc_state->port_clock,
>> + crtc_state->lane_count);
>
> Nit: looking this up from drm_dp_mst_topology_state (once SST and MST is
> separated done only in the MST case) instead of recalculating the same
> would be better. Either way:
I don't disagree, but I couldn't figure out a neat way to deduplicate
that just yet. This seemed simpler. I think I'll leave that for future
improvement.
> Reviewed-by: Imre Deak <imre.deak at intel.com>
Thanks,
Jani.
>
>>
>> max_dpt_bpp = intel_dp_mst_max_dpt_bpp(crtc_state, dsc);
>> if (max_bpp > max_dpt_bpp) {
>> @@ -302,7 +294,7 @@ static int mst_stream_find_vcpi_slots_for_bpp(struct intel_dp *intel_dp,
>> pbn.full = dfixed_const(intel_dp_mst_calc_pbn(adjusted_mode->crtc_clock,
>> link_bpp_x16,
>> remote_bw_overhead));
>> - remote_tu = DIV_ROUND_UP(pbn.full, mst_state->pbn_div.full);
>> + remote_tu = DIV_ROUND_UP(pbn.full, pbn_div.full);
>>
>> /*
>> * Aligning the TUs ensures that symbols consisting of multiple
>> @@ -320,7 +312,7 @@ static int mst_stream_find_vcpi_slots_for_bpp(struct intel_dp *intel_dp,
>> * allocated for the whole path and the TUs allocated for the
>> * first branch device's link also applies here.
>> */
>> - pbn.full = remote_tu * mst_state->pbn_div.full;
>> + pbn.full = remote_tu * pbn_div.full;
>>
>> drm_WARN_ON(display->drm, remote_tu < crtc_state->dp_m_n.tu);
>> crtc_state->dp_m_n.tu = remote_tu;
>> @@ -355,6 +347,31 @@ static int mst_stream_find_vcpi_slots_for_bpp(struct intel_dp *intel_dp,
>> return 0;
>> }
>>
>> +static int mst_stream_find_vcpi_slots_for_bpp(struct intel_dp *intel_dp,
>> + struct intel_crtc_state *crtc_state,
>> + int max_bpp, int min_bpp,
>> + struct link_config_limits *limits,
>> + struct drm_connector_state *conn_state,
>> + int step, bool dsc)
>> +{
>> + struct drm_atomic_state *state = crtc_state->uapi.state;
>> + struct drm_dp_mst_topology_state *mst_state;
>> +
>> + mst_state = drm_atomic_get_mst_topology_state(state, &intel_dp->mst_mgr);
>> + if (IS_ERR(mst_state))
>> + return PTR_ERR(mst_state);
>> +
>> + crtc_state->lane_count = limits->max_lane_count;
>> + crtc_state->port_clock = limits->max_rate;
>> +
>> + mst_state->pbn_div = drm_dp_get_vc_payload_bw(crtc_state->port_clock,
>> + crtc_state->lane_count);
>> +
>> + return intel_dp_mtp_tu_compute_config(intel_dp, crtc_state,
>> + max_bpp, min_bpp,
>> + conn_state, step, dsc);
>> +}
>> +
>> static int mst_stream_compute_link_config(struct intel_dp *intel_dp,
>> struct intel_crtc_state *crtc_state,
>> struct drm_connector_state *conn_state,
>> diff --git a/drivers/gpu/drm/i915/display/intel_dp_mst.h b/drivers/gpu/drm/i915/display/intel_dp_mst.h
>> index 8343804ce3f8..c6bdc1d190a4 100644
>> --- a/drivers/gpu/drm/i915/display/intel_dp_mst.h
>> +++ b/drivers/gpu/drm/i915/display/intel_dp_mst.h
>> @@ -8,6 +8,7 @@
>>
>> #include <linux/types.h>
>>
>> +struct drm_connector_state;
>> struct intel_atomic_state;
>> struct intel_crtc;
>> struct intel_crtc_state;
>> @@ -30,4 +31,10 @@ bool intel_dp_mst_crtc_needs_modeset(struct intel_atomic_state *state,
>> void intel_dp_mst_prepare_probe(struct intel_dp *intel_dp);
>> bool intel_dp_mst_verify_dpcd_state(struct intel_dp *intel_dp);
>>
>> +int intel_dp_mtp_tu_compute_config(struct intel_dp *intel_dp,
>> + struct intel_crtc_state *crtc_state,
>> + int max_bpp, int min_bpp,
>> + struct drm_connector_state *conn_state,
>> + int step, bool dsc);
>> +
>> #endif /* __INTEL_DP_MST_H__ */
>> --
>> 2.39.5
>>
--
Jani Nikula, Intel
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