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path: root/drivers/gpu/drm/i915/display/intel_dp_mst.c
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Diffstat (limited to 'drivers/gpu/drm/i915/display/intel_dp_mst.c')
-rw-r--r--drivers/gpu/drm/i915/display/intel_dp_mst.c106
1 files changed, 74 insertions, 32 deletions
diff --git a/drivers/gpu/drm/i915/display/intel_dp_mst.c b/drivers/gpu/drm/i915/display/intel_dp_mst.c
index d43617734009..c772ba19c547 100644
--- a/drivers/gpu/drm/i915/display/intel_dp_mst.c
+++ b/drivers/gpu/drm/i915/display/intel_dp_mst.c
@@ -51,25 +51,39 @@
#include "intel_vdsc.h"
#include "skl_scaler.h"
-static int intel_dp_mst_check_constraints(struct drm_i915_private *i915, int bpp,
- const struct drm_display_mode *adjusted_mode,
- struct intel_crtc_state *crtc_state,
- bool dsc)
+static int intel_dp_mst_max_dpt_bpp(const struct intel_crtc_state *crtc_state,
+ bool dsc)
{
- if (intel_dp_is_uhbr(crtc_state) && DISPLAY_VER(i915) < 14 && dsc) {
- int output_bpp = bpp;
- /* DisplayPort 2 128b/132b, bits per lane is always 32 */
- int symbol_clock = crtc_state->port_clock / 32;
-
- if (output_bpp * adjusted_mode->crtc_clock >=
- symbol_clock * 72) {
- drm_dbg_kms(&i915->drm, "UHBR check failed(required bw %d available %d)\n",
- output_bpp * adjusted_mode->crtc_clock, symbol_clock * 72);
- return -EINVAL;
- }
- }
+ struct drm_i915_private *i915 = to_i915(crtc_state->uapi.crtc->dev);
+ const struct drm_display_mode *adjusted_mode =
+ &crtc_state->hw.adjusted_mode;
- return 0;
+ if (!intel_dp_is_uhbr(crtc_state) || DISPLAY_VER(i915) >= 20 || !dsc)
+ return INT_MAX;
+
+ /*
+ * DSC->DPT interface width:
+ * ICL-MTL: 72 bits (each branch has 72 bits, only left branch is used)
+ * LNL+: 144 bits (not a bottleneck in any config)
+ *
+ * Bspec/49259 suggests that the FEC overhead needs to be
+ * applied here, though HW people claim that neither this FEC
+ * or any other overhead is applicable here (that is the actual
+ * available_bw is just symbol_clock * 72). However based on
+ * testing on MTL-P the
+ * - DELL U3224KBA display
+ * - Unigraf UCD-500 CTS test sink
+ * devices the
+ * - 5120x2880/995.59Mhz
+ * - 6016x3384/1357.23Mhz
+ * - 6144x3456/1413.39Mhz
+ * modes (all the ones having a DPT limit on the above devices),
+ * both the channel coding efficiency and an additional 3%
+ * overhead needs to be accounted for.
+ */
+ return div64_u64(mul_u32_u32(intel_dp_link_symbol_clock(crtc_state->port_clock) * 72,
+ drm_dp_bw_channel_coding_efficiency(true)),
+ mul_u32_u32(adjusted_mode->crtc_clock, 1030000));
}
static int intel_dp_mst_bw_overhead(const struct intel_crtc_state *crtc_state,
@@ -157,6 +171,7 @@ static int intel_dp_mst_find_vcpi_slots_for_bpp(struct intel_encoder *encoder,
const struct drm_display_mode *adjusted_mode =
&crtc_state->hw.adjusted_mode;
int bpp, slots = -EINVAL;
+ int max_dpt_bpp;
int ret = 0;
mst_state = drm_atomic_get_mst_topology_state(state, &intel_dp->mst_mgr);
@@ -177,6 +192,13 @@ static int intel_dp_mst_find_vcpi_slots_for_bpp(struct intel_encoder *encoder,
crtc_state->port_clock,
crtc_state->lane_count);
+ max_dpt_bpp = intel_dp_mst_max_dpt_bpp(crtc_state, dsc);
+ if (max_bpp > max_dpt_bpp) {
+ drm_dbg_kms(&i915->drm, "Limiting bpp to max DPT bpp (%d -> %d)\n",
+ max_bpp, max_dpt_bpp);
+ max_bpp = max_dpt_bpp;
+ }
+
drm_dbg_kms(&i915->drm, "Looking for slots in range min bpp %d max bpp %d\n",
min_bpp, max_bpp);
@@ -188,10 +210,6 @@ static int intel_dp_mst_find_vcpi_slots_for_bpp(struct intel_encoder *encoder,
drm_dbg_kms(&i915->drm, "Trying bpp %d\n", bpp);
- ret = intel_dp_mst_check_constraints(i915, bpp, adjusted_mode, crtc_state, dsc);
- if (ret)
- continue;
-
link_bpp_x16 = to_bpp_x16(dsc ? bpp :
intel_dp_output_bpp(crtc_state->output_format, bpp));
@@ -403,15 +421,22 @@ static int mode_hblank_period_ns(const struct drm_display_mode *mode)
static bool
hblank_expansion_quirk_needs_dsc(const struct intel_connector *connector,
- const struct intel_crtc_state *crtc_state)
+ const struct intel_crtc_state *crtc_state,
+ const struct link_config_limits *limits)
{
const struct drm_display_mode *adjusted_mode =
&crtc_state->hw.adjusted_mode;
+ bool is_uhbr_sink = connector->mst_port &&
+ drm_dp_128b132b_supported(connector->mst_port->dpcd);
+ int hblank_limit = is_uhbr_sink ? 500 : 300;
if (!connector->dp.dsc_hblank_expansion_quirk)
return false;
- if (mode_hblank_period_ns(adjusted_mode) > 300)
+ if (is_uhbr_sink && !drm_dp_is_uhbr_rate(limits->max_rate))
+ return false;
+
+ if (mode_hblank_period_ns(adjusted_mode) > hblank_limit)
return false;
return true;
@@ -427,7 +452,7 @@ adjust_limits_for_dsc_hblank_expansion_quirk(const struct intel_connector *conne
const struct intel_crtc *crtc = to_intel_crtc(crtc_state->uapi.crtc);
int min_bpp_x16 = limits->link.min_bpp_x16;
- if (!hblank_expansion_quirk_needs_dsc(connector, crtc_state))
+ if (!hblank_expansion_quirk_needs_dsc(connector, crtc_state, limits))
return true;
if (!dsc) {
@@ -620,7 +645,7 @@ static int intel_dp_mst_compute_config(struct intel_encoder *encoder,
if (IS_GEMINILAKE(dev_priv) || IS_BROXTON(dev_priv))
pipe_config->lane_lat_optim_mask =
- bxt_ddi_phy_calc_lane_lat_optim_mask(pipe_config->lane_count);
+ bxt_dpio_phy_calc_lane_lat_optim_mask(pipe_config->lane_count);
intel_dp_audio_compute_config(encoder, pipe_config, conn_state);
@@ -1559,24 +1584,41 @@ intel_dp_mst_read_decompression_port_dsc_caps(struct intel_dp *intel_dp,
static bool detect_dsc_hblank_expansion_quirk(const struct intel_connector *connector)
{
struct drm_i915_private *i915 = to_i915(connector->base.dev);
+ struct drm_dp_aux *aux = connector->dp.dsc_decompression_aux;
struct drm_dp_desc desc;
u8 dpcd[DP_RECEIVER_CAP_SIZE];
- if (!connector->dp.dsc_decompression_aux)
+ if (!aux)
+ return false;
+
+ /*
+ * A logical port's OUI (at least for affected sinks) is all 0, so
+ * instead of that the parent port's OUI is used for identification.
+ */
+ if (drm_dp_mst_port_is_logical(connector->port)) {
+ aux = drm_dp_mst_aux_for_parent(connector->port);
+ if (!aux)
+ aux = &connector->mst_port->aux;
+ }
+
+ if (drm_dp_read_dpcd_caps(aux, dpcd) < 0)
return false;
- if (drm_dp_read_desc(connector->dp.dsc_decompression_aux,
- &desc, true) < 0)
+ if (drm_dp_read_desc(aux, &desc, drm_dp_is_branch(dpcd)) < 0)
return false;
if (!drm_dp_has_quirk(&desc,
DP_DPCD_QUIRK_HBLANK_EXPANSION_REQUIRES_DSC))
return false;
- if (drm_dp_read_dpcd_caps(connector->dp.dsc_decompression_aux, dpcd) < 0)
- return false;
-
- if (!(dpcd[DP_RECEIVE_PORT_0_CAP_0] & DP_HBLANK_EXPANSION_CAPABLE))
+ /*
+ * UHBR (MST sink) devices requiring this quirk don't advertise the
+ * HBLANK expansion support. Presuming that they perform HBLANK
+ * expansion internally, or are affected by this issue on modes with a
+ * short HBLANK for other reasons.
+ */
+ if (!drm_dp_128b132b_supported(dpcd) &&
+ !(dpcd[DP_RECEIVE_PORT_0_CAP_0] & DP_HBLANK_EXPANSION_CAPABLE))
return false;
drm_dbg_kms(&i915->drm,