[PATCH 2/2] drm/i915: Add DSC support to MST path
Stanislav Lisovskiy
stanislav.lisovskiy at intel.com
Wed Aug 10 08:17:53 UTC 2022
Whenever we are not able to get enough timeslots
for required PBN, let's try to allocate those
using DSC, just same way as we do for SST.
v2: Removed intel_dp_mst_dsc_compute_config and refactored
intel_dp_dsc_compute_config to support timeslots as a
parameter(Ville Syrjälä)
v3: - Rebased
- Added a debug to see that we at least try reserving
VCPI slots using DSC, because currently its not visible
from the logs, thus making debugging more tricky.
- Moved timeslots to numerator, where it should be.
Signed-off-by: Stanislav Lisovskiy <stanislav.lisovskiy at intel.com>
---
drivers/gpu/drm/i915/display/intel_dp.c | 76 +++++-----
drivers/gpu/drm/i915/display/intel_dp.h | 17 +++
drivers/gpu/drm/i915/display/intel_dp_mst.c | 145 ++++++++++++++++++++
3 files changed, 194 insertions(+), 44 deletions(-)
diff --git a/drivers/gpu/drm/i915/display/intel_dp.c b/drivers/gpu/drm/i915/display/intel_dp.c
index 32292c0be2bd..1f6dc52251c2 100644
--- a/drivers/gpu/drm/i915/display/intel_dp.c
+++ b/drivers/gpu/drm/i915/display/intel_dp.c
@@ -116,7 +116,6 @@ bool intel_dp_is_edp(struct intel_dp *intel_dp)
}
static void intel_dp_unset_edid(struct intel_dp *intel_dp);
-static int intel_dp_dsc_compute_bpp(struct intel_dp *intel_dp, u8 dsc_max_bpc);
/* Is link rate UHBR and thus 128b/132b? */
bool intel_dp_is_uhbr(const struct intel_crtc_state *crtc_state)
@@ -687,11 +686,12 @@ small_joiner_ram_size_bits(struct drm_i915_private *i915)
return 6144 * 8;
}
-static u16 intel_dp_dsc_get_output_bpp(struct drm_i915_private *i915,
- u32 link_clock, u32 lane_count,
- u32 mode_clock, u32 mode_hdisplay,
- bool bigjoiner,
- u32 pipe_bpp)
+u16 intel_dp_dsc_get_output_bpp(struct drm_i915_private *i915,
+ u32 link_clock, u32 lane_count,
+ u32 mode_clock, u32 mode_hdisplay,
+ bool bigjoiner,
+ u32 pipe_bpp,
+ u32 timeslots)
{
u32 bits_per_pixel, max_bpp_small_joiner_ram;
int i;
@@ -702,8 +702,9 @@ static u16 intel_dp_dsc_get_output_bpp(struct drm_i915_private *i915,
* for SST -> TimeSlotsPerMTP is 1,
* for MST -> TimeSlotsPerMTP has to be calculated
*/
- bits_per_pixel = (link_clock * lane_count * 8) /
+ bits_per_pixel = (link_clock * lane_count * 8) * timeslots /
intel_dp_mode_to_fec_clock(mode_clock);
+ drm_dbg_kms(&i915->drm, "Max link bpp: %u\n", bits_per_pixel);
/* Small Joiner Check: output bpp <= joiner RAM (bits) / Horiz. width */
max_bpp_small_joiner_ram = small_joiner_ram_size_bits(i915) /
@@ -752,9 +753,9 @@ static u16 intel_dp_dsc_get_output_bpp(struct drm_i915_private *i915,
return bits_per_pixel << 4;
}
-static u8 intel_dp_dsc_get_slice_count(struct intel_dp *intel_dp,
- int mode_clock, int mode_hdisplay,
- bool bigjoiner)
+u8 intel_dp_dsc_get_slice_count(struct intel_dp *intel_dp,
+ int mode_clock, int mode_hdisplay,
+ bool bigjoiner)
{
struct drm_i915_private *i915 = dp_to_i915(intel_dp);
u8 min_slice_count, i;
@@ -961,8 +962,8 @@ intel_dp_mode_valid_downstream(struct intel_connector *connector,
return MODE_OK;
}
-static bool intel_dp_need_bigjoiner(struct intel_dp *intel_dp,
- int hdisplay, int clock)
+bool intel_dp_need_bigjoiner(struct intel_dp *intel_dp,
+ int hdisplay, int clock)
{
struct drm_i915_private *i915 = dp_to_i915(intel_dp);
@@ -1049,7 +1050,7 @@ intel_dp_mode_valid(struct drm_connector *_connector,
target_clock,
mode->hdisplay,
bigjoiner,
- pipe_bpp) >> 4;
+ pipe_bpp, 1) >> 4;
dsc_slice_count =
intel_dp_dsc_get_slice_count(intel_dp,
target_clock,
@@ -1354,7 +1355,7 @@ intel_dp_compute_link_config_wide(struct intel_dp *intel_dp,
return -EINVAL;
}
-static int intel_dp_dsc_compute_bpp(struct intel_dp *intel_dp, u8 max_req_bpc)
+int intel_dp_dsc_compute_bpp(struct intel_dp *intel_dp, u8 max_req_bpc)
{
struct drm_i915_private *i915 = dp_to_i915(intel_dp);
int i, num_bpc;
@@ -1444,10 +1445,11 @@ static int intel_dp_dsc_compute_params(struct intel_encoder *encoder,
return drm_dsc_compute_rc_parameters(vdsc_cfg);
}
-static int intel_dp_dsc_compute_config(struct intel_dp *intel_dp,
- struct intel_crtc_state *pipe_config,
- struct drm_connector_state *conn_state,
- struct link_config_limits *limits)
+int intel_dp_dsc_compute_config(struct intel_dp *intel_dp,
+ struct intel_crtc_state *pipe_config,
+ struct drm_connector_state *conn_state,
+ struct link_config_limits *limits,
+ int timeslots)
{
struct intel_digital_port *dig_port = dp_to_dig_port(intel_dp);
struct drm_i915_private *dev_priv = to_i915(dig_port->base.base.dev);
@@ -1498,7 +1500,8 @@ static int intel_dp_dsc_compute_config(struct intel_dp *intel_dp,
adjusted_mode->crtc_clock,
adjusted_mode->crtc_hdisplay,
pipe_config->bigjoiner_pipes,
- pipe_bpp);
+ pipe_bpp,
+ timeslots);
dsc_dp_slice_count =
intel_dp_dsc_get_slice_count(intel_dp,
adjusted_mode->crtc_clock,
@@ -1510,41 +1513,26 @@ static int intel_dp_dsc_compute_config(struct intel_dp *intel_dp,
return -EINVAL;
}
pipe_config->dsc.compressed_bpp = min_t(u16,
- dsc_max_output_bpp >> 4,
- pipe_config->pipe_bpp);
+ dsc_max_output_bpp >> 4,
+ pipe_config->pipe_bpp);
pipe_config->dsc.slice_count = dsc_dp_slice_count;
+ drm_dbg_kms(&dev_priv->drm, "DSC: compressed bpp %d slice count %d\n",
+ pipe_config->dsc.compressed_bpp,
+ pipe_config->dsc.slice_count);
}
-
- /* As of today we support DSC for only RGB */
- if (intel_dp->force_dsc_bpp) {
- if (intel_dp->force_dsc_bpp >= 8 &&
- intel_dp->force_dsc_bpp < pipe_bpp) {
- drm_dbg_kms(&dev_priv->drm,
- "DSC BPP forced to %d",
- intel_dp->force_dsc_bpp);
- pipe_config->dsc.compressed_bpp =
- intel_dp->force_dsc_bpp;
- } else {
- drm_dbg_kms(&dev_priv->drm,
- "Invalid DSC BPP %d",
- intel_dp->force_dsc_bpp);
- }
- }
-
/*
* VDSC engine operates at 1 Pixel per clock, so if peak pixel rate
* is greater than the maximum Cdclock and if slice count is even
* then we need to use 2 VDSC instances.
*/
- if (adjusted_mode->crtc_clock > dev_priv->max_cdclk_freq ||
- pipe_config->bigjoiner_pipes) {
- if (pipe_config->dsc.slice_count < 2) {
+ if (adjusted_mode->crtc_clock > dev_priv->max_cdclk_freq) {
+ if (pipe_config->dsc.slice_count > 1) {
+ pipe_config->dsc.dsc_split = true;
+ } else {
drm_dbg_kms(&dev_priv->drm,
"Cannot split stream to use 2 VDSC instances\n");
return -EINVAL;
}
-
- pipe_config->dsc.dsc_split = true;
}
ret = intel_dp_dsc_compute_params(&dig_port->base, pipe_config);
@@ -1633,7 +1621,7 @@ intel_dp_compute_link_config(struct intel_encoder *encoder,
str_yes_no(ret), str_yes_no(joiner_needs_dsc),
str_yes_no(intel_dp->force_dsc_en));
ret = intel_dp_dsc_compute_config(intel_dp, pipe_config,
- conn_state, &limits);
+ conn_state, &limits, 1);
if (ret < 0)
return ret;
}
diff --git a/drivers/gpu/drm/i915/display/intel_dp.h b/drivers/gpu/drm/i915/display/intel_dp.h
index a54902c713a3..c6539a6915e9 100644
--- a/drivers/gpu/drm/i915/display/intel_dp.h
+++ b/drivers/gpu/drm/i915/display/intel_dp.h
@@ -56,6 +56,11 @@ void intel_dp_encoder_flush_work(struct drm_encoder *encoder);
int intel_dp_compute_config(struct intel_encoder *encoder,
struct intel_crtc_state *pipe_config,
struct drm_connector_state *conn_state);
+int intel_dp_dsc_compute_config(struct intel_dp *intel_dp,
+ struct intel_crtc_state *pipe_config,
+ struct drm_connector_state *conn_state,
+ struct link_config_limits *limits,
+ int timeslots);
bool intel_dp_is_edp(struct intel_dp *intel_dp);
bool intel_dp_is_uhbr(const struct intel_crtc_state *crtc_state);
bool intel_dp_is_port_edp(struct drm_i915_private *dev_priv, enum port port);
@@ -96,6 +101,18 @@ void intel_read_dp_sdp(struct intel_encoder *encoder,
struct intel_crtc_state *crtc_state,
unsigned int type);
bool intel_digital_port_connected(struct intel_encoder *encoder);
+int intel_dp_dsc_compute_bpp(struct intel_dp *intel_dp, u8 dsc_max_bpc);
+u16 intel_dp_dsc_get_output_bpp(struct drm_i915_private *i915,
+ u32 link_clock, u32 lane_count,
+ u32 mode_clock, u32 mode_hdisplay,
+ bool bigjoiner,
+ u32 pipe_bpp,
+ u32 timeslots);
+u8 intel_dp_dsc_get_slice_count(struct intel_dp *intel_dp,
+ int mode_clock, int mode_hdisplay,
+ bool bigjoiner);
+bool intel_dp_need_bigjoiner(struct intel_dp *intel_dp,
+ int hdisplay, int clock);
static inline unsigned int intel_dp_unused_lane_mask(int lane_count)
{
diff --git a/drivers/gpu/drm/i915/display/intel_dp_mst.c b/drivers/gpu/drm/i915/display/intel_dp_mst.c
index 14d2a64193b2..b57f4db5b868 100644
--- a/drivers/gpu/drm/i915/display/intel_dp_mst.c
+++ b/drivers/gpu/drm/i915/display/intel_dp_mst.c
@@ -99,6 +99,82 @@ static int intel_dp_mst_compute_link_config(struct intel_encoder *encoder,
return 0;
}
+static int intel_dp_dsc_mst_compute_link_config(struct intel_encoder *encoder,
+ struct intel_crtc_state *crtc_state,
+ struct drm_connector_state *conn_state,
+ struct link_config_limits *limits)
+{
+ struct drm_atomic_state *state = crtc_state->uapi.state;
+ struct intel_dp_mst_encoder *intel_mst = enc_to_mst(encoder);
+ struct intel_dp *intel_dp = &intel_mst->primary->dp;
+ struct intel_connector *connector =
+ to_intel_connector(conn_state->connector);
+ struct drm_i915_private *i915 = to_i915(connector->base.dev);
+ const struct drm_display_mode *adjusted_mode =
+ &crtc_state->hw.adjusted_mode;
+ bool constant_n = drm_dp_has_quirk(&intel_dp->desc,
+ DP_DPCD_QUIRK_CONSTANT_N);
+ int bpp, slots = -EINVAL;
+ int i, num_bpc;
+ u8 dsc_bpc[3] = {0};
+ int min_bpp, max_bpp;
+ u8 dsc_max_bpc;
+
+ crtc_state->lane_count = limits->max_lane_count;
+ crtc_state->port_clock = limits->max_rate;
+
+ /* Max DSC Input BPC for ICL is 10 and for TGL+ is 12 */
+ if (DISPLAY_VER(i915) >= 12)
+ dsc_max_bpc = min_t(u8, 12, conn_state->max_requested_bpc);
+ else
+ dsc_max_bpc = min_t(u8, 10, conn_state->max_requested_bpc);
+
+ max_bpp = min_t(u8, dsc_max_bpc * 3, limits->max_bpp);
+ min_bpp = limits->min_bpp;
+
+ num_bpc = drm_dp_dsc_sink_supported_input_bpcs(intel_dp->dsc_dpcd,
+ dsc_bpc);
+ for (i = 0; i < num_bpc; i++) {
+ if (max_bpp >= dsc_bpc[i] * 3)
+ if (min_bpp > dsc_bpc[i] * 3)
+ min_bpp = dsc_bpc[i] * 3;
+ }
+ drm_dbg_kms(&i915->drm, "DSC Sink supported min bpp %d max bpp %d\n",
+ min_bpp, max_bpp);
+ for (bpp = max_bpp; bpp >= min_bpp; bpp -= 2 * 3) {
+ crtc_state->pbn = drm_dp_calc_pbn_mode(adjusted_mode->crtc_clock,
+ bpp << 4,
+ true);
+
+ slots = drm_dp_atomic_find_vcpi_slots(state, &intel_dp->mst_mgr,
+ connector->port,
+ crtc_state->pbn, 0);
+
+ drm_dbg_kms(&i915->drm, "Trying bpp %d got %d pbn %d slots\n",
+ bpp, crtc_state->pbn, slots);
+
+ if (slots == -EDEADLK)
+ return slots;
+ if (slots >= 0)
+ break;
+ }
+
+ if (slots < 0) {
+ drm_dbg_kms(&i915->drm, "failed finding vcpi slots:%d\n",
+ slots);
+ return slots;
+ }
+
+ intel_link_compute_m_n(crtc_state->pipe_bpp,
+ crtc_state->lane_count,
+ adjusted_mode->crtc_clock,
+ crtc_state->port_clock,
+ &crtc_state->dp_m_n,
+ constant_n, crtc_state->fec_enable);
+ crtc_state->dp_m_n.tu = slots;
+
+ return 0;
+}
static int intel_dp_mst_update_slots(struct intel_encoder *encoder,
struct intel_crtc_state *crtc_state,
struct drm_connector_state *conn_state)
@@ -175,6 +251,29 @@ static int intel_dp_mst_compute_config(struct intel_encoder *encoder,
ret = intel_dp_mst_compute_link_config(encoder, pipe_config,
conn_state, &limits);
+
+ if (ret == -EDEADLK)
+ return ret;
+
+ /* enable compression if the mode doesn't fit available BW */
+ drm_dbg_kms(&dev_priv->drm, "Force DSC en = %d\n", intel_dp->force_dsc_en);
+ if (ret || intel_dp->force_dsc_en) {
+ /*
+ * Try to get at least some timeslots and then see, if
+ * we can fit there with DSC.
+ */
+ drm_dbg_kms(&dev_priv->drm, "Trying to find VCPI slots in DSC mode\n");
+
+ ret = intel_dp_dsc_mst_compute_link_config(encoder, pipe_config,
+ conn_state, &limits);
+ if (ret < 0)
+ return ret;
+
+ ret = intel_dp_dsc_compute_config(intel_dp, pipe_config,
+ conn_state, &limits,
+ pipe_config->dp_m_n.tu);
+ }
+
if (ret)
return ret;
@@ -713,6 +812,10 @@ intel_dp_mst_mode_valid_ctx(struct drm_connector *connector,
int max_dotclk = to_i915(connector->dev)->max_dotclk_freq;
int max_rate, mode_rate, max_lanes, max_link_clock;
int ret;
+ bool dsc = false, bigjoiner = false;
+ u16 dsc_max_output_bpp = 0;
+ u8 dsc_slice_count = 0;
+ int target_clock = mode->clock;
if (drm_connector_is_unregistered(connector)) {
*status = MODE_ERROR;
@@ -750,6 +853,48 @@ intel_dp_mst_mode_valid_ctx(struct drm_connector *connector,
return 0;
}
+ if (intel_dp_need_bigjoiner(intel_dp, mode->hdisplay, target_clock)) {
+ bigjoiner = true;
+ max_dotclk *= 2;
+ }
+
+ if (DISPLAY_VER(dev_priv) >= 10 &&
+ drm_dp_sink_supports_dsc(intel_dp->dsc_dpcd)) {
+ /*
+ * TBD pass the connector BPC,
+ * for now U8_MAX so that max BPC on that platform would be picked
+ */
+ int pipe_bpp = intel_dp_dsc_compute_bpp(intel_dp, U8_MAX);
+
+ if (drm_dp_sink_supports_fec(intel_dp->fec_capable)) {
+ dsc_max_output_bpp =
+ intel_dp_dsc_get_output_bpp(dev_priv,
+ max_link_clock,
+ max_lanes,
+ target_clock,
+ mode->hdisplay,
+ bigjoiner,
+ pipe_bpp, 1) >> 4;
+ dsc_slice_count =
+ intel_dp_dsc_get_slice_count(intel_dp,
+ target_clock,
+ mode->hdisplay,
+ bigjoiner);
+ }
+
+ dsc = dsc_max_output_bpp && dsc_slice_count;
+ }
+
+ /*
+ * Big joiner configuration needs DSC for TGL which is not true for
+ * XE_LPD where uncompressed joiner is supported.
+ */
+ if (DISPLAY_VER(dev_priv) < 13 && bigjoiner && !dsc)
+ return MODE_CLOCK_HIGH;
+
+ if (mode_rate > max_rate && !dsc)
+ return MODE_CLOCK_HIGH;
+
*status = intel_mode_valid_max_plane_size(dev_priv, mode, false);
return 0;
}
--
2.24.1.485.gad05a3d8e5
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