[PATCH 5/9] drm/i915/display: check and prune audio frequencies based on bw limits
Vinod Govindapillai
vinod.govindapillai at intel.com
Tue Oct 8 08:23:23 UTC 2024
Calculate the audio bw requirements and check the supported sad
audio frequencies are feasible with selected pipe configuration.
If not feasible, prune the audio frequencies from sad list.
Bspec: 67768
Signed-off-by: Vinod Govindapillai <vinod.govindapillai at intel.com>
---
drivers/gpu/drm/i915/display/intel_audio.c | 107 +++++++++++++++++++++
drivers/gpu/drm/i915/display/intel_audio.h | 3 +
drivers/gpu/drm/i915/display/intel_dp.c | 50 ++++++++++
3 files changed, 160 insertions(+)
diff --git a/drivers/gpu/drm/i915/display/intel_audio.c b/drivers/gpu/drm/i915/display/intel_audio.c
index 6946f3b0f8c9..e84101ef9531 100644
--- a/drivers/gpu/drm/i915/display/intel_audio.c
+++ b/drivers/gpu/drm/i915/display/intel_audio.c
@@ -705,6 +705,113 @@ static bool intel_audio_eld_valid(struct drm_connector_state *conn_state)
return true;
}
+static bool
+intel_audio_frequency_feasible(int line_freq_khz, int hblank_slots_lanes,
+ int avail_overhead, int req_overhead,
+ int channels, int aud_frequency)
+{
+ int aud_samples_per_line =
+ DIV_ROUND_UP(aud_frequency, line_freq_khz) + 1;
+ int lines_per_audio_sample =
+ max(1, line_freq_khz / aud_frequency);
+ int hblank_bytes_available =
+ (hblank_slots_lanes - avail_overhead) * lines_per_audio_sample;
+ int hblank_bytes_required;
+
+ if (channels > 2)
+ hblank_bytes_required =
+ DIV_ROUND_UP(aud_samples_per_line * 10 + 2, 4) * 16 + req_overhead;
+ else
+ hblank_bytes_required =
+ (DIV_ROUND_UP(DIV_ROUND_UP(aud_samples_per_line, 2) * 5 + 2, 4) + 2) * 16 + req_overhead;
+
+ return hblank_bytes_available > hblank_bytes_required;
+}
+
+static u8
+intel_audio_get_pruned_audfreq(struct drm_i915_private *i915,
+ int line_freq_khz, int hblank_slots_lanes,
+ int avail_overhead, int req_overhead,
+ int channels, u8 in_sad_freq)
+{
+ const unsigned int freq_list_khz[] = { 32, 44, 48, 88, 96, 176, 192 };
+ u8 pruned_sad_freq = in_sad_freq;
+
+ for (int j = ARRAY_SIZE(freq_list_khz) - 1; j >= 0; j--) {
+ int freq = pruned_sad_freq & BIT(j) ? freq_list_khz[j] : 0;
+
+ if (!freq)
+ continue;
+
+ /* If "freq" is ok, then values below are also ok */
+ if (intel_audio_frequency_feasible(line_freq_khz,
+ hblank_slots_lanes,
+ avail_overhead,
+ req_overhead,
+ channels, freq))
+ break;
+
+ /* "freq" not feasible! Prune it from the list */
+ pruned_sad_freq &= ~BIT(j);
+ drm_dbg_kms(&i915->drm,
+ "Frequency[%d]: %d channels: %d not feasible\n",
+ j, freq, channels);
+ }
+
+ return pruned_sad_freq;
+}
+
+static void intel_audio_compute_sad(struct drm_i915_private *i915,
+ int line_freq_khz, int hblank_slots_lanes,
+ int avail_overhead, int req_overhead,
+ struct cea_sad *sad)
+{
+ u8 sad_channels = sad->channels + 1;
+ u8 sad_freq;
+
+ sad_freq = intel_audio_get_pruned_audfreq(i915, line_freq_khz,
+ hblank_slots_lanes,
+ avail_overhead,
+ req_overhead, sad_channels,
+ sad->freq);
+
+ sad->freq = sad_freq;
+}
+
+bool intel_audio_compute_eld_config(struct drm_connector_state *conn_state,
+ int line_freq_khz, int hblank_slots_lanes,
+ int avail_overhead, int req_overhead)
+{
+ struct drm_connector *connector = conn_state->connector;
+ struct drm_i915_private *i915 = to_i915(connector->dev);
+ u8 *eld;
+
+ if (!intel_audio_eld_valid(conn_state))
+ return false;
+
+ eld = connector->eld;
+ for (int i = 0; i < drm_eld_sad_count(eld); i++) {
+ struct cea_sad sad;
+ u8 sad_freq;
+
+ if (drm_eld_sad_get(eld, i, &sad))
+ continue;
+
+ sad_freq = sad.freq;
+ intel_audio_compute_sad(i915, line_freq_khz,
+ hblank_slots_lanes,
+ avail_overhead, req_overhead, &sad);
+
+ /* Update the eld with new sad data if any changes in the list */
+ if (sad_freq != sad.freq) {
+ drm_eld_sad_set(eld, i, &sad);
+ drm_dbg_kms(&i915->drm, "sad updated. Pruned freq list: 0x%x\n", sad.freq);
+ }
+ }
+
+ return true;
+}
+
bool intel_audio_compute_config(struct intel_crtc_state *crtc_state,
struct drm_connector_state *conn_state)
{
diff --git a/drivers/gpu/drm/i915/display/intel_audio.h b/drivers/gpu/drm/i915/display/intel_audio.h
index 9b327b677d89..f8574fc30973 100644
--- a/drivers/gpu/drm/i915/display/intel_audio.h
+++ b/drivers/gpu/drm/i915/display/intel_audio.h
@@ -30,5 +30,8 @@ void intel_audio_init(struct drm_i915_private *dev_priv);
void intel_audio_register(struct drm_i915_private *i915);
void intel_audio_deinit(struct drm_i915_private *dev_priv);
void intel_audio_sdp_split_update(const struct intel_crtc_state *crtc_state);
+bool intel_audio_compute_eld_config(struct drm_connector_state *conn_state,
+ int line_freq_khz, int hblank_slots_lanes,
+ int avail_overhead, int req_overhead);
#endif /* __INTEL_AUDIO_H__ */
diff --git a/drivers/gpu/drm/i915/display/intel_dp.c b/drivers/gpu/drm/i915/display/intel_dp.c
index 6347258b4a49..dde7244ccd15 100644
--- a/drivers/gpu/drm/i915/display/intel_dp.c
+++ b/drivers/gpu/drm/i915/display/intel_dp.c
@@ -2994,6 +2994,53 @@ intel_dp_compute_output_format(struct intel_encoder *encoder,
return ret;
}
+static void
+intel_dp_compute_audio_bwparams(struct intel_crtc_state *crtc_state,
+ int *line_freq_khz, int *hblank_slots_lanes)
+{
+ /* Calculation steps based on Bspec: 67768 */
+ struct drm_display_mode *adjusted_mode = &crtc_state->hw.adjusted_mode;
+ int link_rate_mhz = DIV_ROUND_UP(crtc_state->port_clock, 1000);
+ int pixel_clk_mhz = DIV_ROUND_UP(adjusted_mode->crtc_clock, 1000);
+ int htotal = adjusted_mode->crtc_htotal;
+ int hblank_pixels =
+ adjusted_mode->crtc_hblank_end - adjusted_mode->crtc_hblank_start;
+ int mtp_clks_per_slot = DIV_ROUND_UP(4, crtc_state->lane_count);
+ int mtp_size_clks = 64 * mtp_clks_per_slot;
+ int link_clk_mhz = DIV_ROUND_UP(link_rate_mhz, 32);
+ int mtp_size_ns = DIV_ROUND_UP(mtp_size_clks * 1000, link_clk_mhz);
+ int hblank_size_ns = DIV_ROUND_UP(hblank_pixels * 1000, pixel_clk_mhz);
+ int mtps_in_hblank = DIV_ROUND_UP(hblank_size_ns, mtp_size_ns);
+ u32 temp = div_u64(mul_u32_u32(mtp_size_clks, crtc_state->dp_m_n.data_m),
+ crtc_state->dp_m_n.data_n);
+ int hblank_slots = mtps_in_hblank * temp;
+
+ *line_freq_khz = DIV_ROUND_UP(pixel_clk_mhz, htotal) * 1000;
+ *hblank_slots_lanes = hblank_slots * crtc_state->lane_count * 4;
+}
+
+static bool
+intel_dp_audio_compute_bw_limits(struct intel_crtc_state *crtc_state,
+ struct drm_connector_state *conn_state)
+{
+ struct drm_i915_private *i915 = to_i915(crtc_state->uapi.crtc->dev);
+ int hblank_bytes_avail_overhead = 64;
+ int hblank_bytes_req_overhead = 80;
+ int hblank_slots_lanes;
+ int line_freq_khz;
+
+ intel_dp_compute_audio_bwparams(crtc_state, &line_freq_khz,
+ &hblank_slots_lanes);
+ drm_dbg_kms(&i915->drm,
+ "bw params: line_freq_khz: %d hblank_slots_lanes: %d\n",
+ line_freq_khz, hblank_slots_lanes);
+
+ return intel_audio_compute_eld_config(conn_state, line_freq_khz,
+ hblank_slots_lanes,
+ hblank_bytes_avail_overhead,
+ hblank_bytes_req_overhead);
+}
+
void
intel_dp_audio_compute_config(struct intel_encoder *encoder,
struct intel_crtc_state *pipe_config,
@@ -3001,6 +3048,9 @@ intel_dp_audio_compute_config(struct intel_encoder *encoder,
{
pipe_config->has_audio = intel_dp_has_audio(encoder, conn_state);
+ pipe_config->has_audio = pipe_config->has_audio &&
+ intel_dp_audio_compute_bw_limits(pipe_config, conn_state);
+
pipe_config->has_audio = pipe_config->has_audio &&
intel_audio_compute_config(pipe_config, conn_state);
--
2.34.1
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