In certain scenarios, we might have to filter out some audio configuration depending on HW limitation. For example, in GLK DP port more than 2 channels are not supported for audio. A monitor provides information of it's supported audio configurations through SAD (Short Audio Descriptors) which are part of the ELD/EDID. In this patch we add a bit mask to indicate which SADs are supported. The bit mask is updated in the function intel_eld_compute_config(). Based on this bit mask, we prune SADs which are not supported in the function i915_audio_component_get_eld() before sending out the data to the audio driver. We use a bit mask instead of operating on the eld data directly as eld data can get updated after intel_eld_compute_config() and before i915_audio_component_get_eld() is called fixes: https://gitlab.freedesktop.org/drm/intel/-/issues/5368 Signed-off-by: Borah, Chaitanya Kumar <chaitanya.kumar.borah@xxxxxxxxx> --- drivers/gpu/drm/drm_edid.c | 36 ++++++++++ drivers/gpu/drm/i915/display/intel_audio.c | 65 ++++++++++++++++++- drivers/gpu/drm/i915/display/intel_audio.h | 3 + drivers/gpu/drm/i915/display/intel_ddi.c | 2 + .../drm/i915/display/intel_display_types.h | 9 +++ include/drm/drm_edid.h | 9 +++ 6 files changed, 123 insertions(+), 1 deletion(-) diff --git a/drivers/gpu/drm/drm_edid.c b/drivers/gpu/drm/drm_edid.c index 90a5e26eafa8..3495af8d8596 100644 --- a/drivers/gpu/drm/drm_edid.c +++ b/drivers/gpu/drm/drm_edid.c @@ -6988,3 +6988,39 @@ static void _drm_update_tile_info(struct drm_connector *connector, connector->tile_group = NULL; } } + +/* + * drm_sad_to_format - extract format of an SAD + * @sad: pointer to an sad + * + * extract the format of an SAD from byte 0 + */ +int drm_sad_to_format(const u8 *sad) +{ + return (sad[0] & DRM_ELD_SAD_FORMAT_MASK) >> DRM_ELD_SAD_FORMAT_SHIFT; +} +EXPORT_SYMBOL(drm_sad_to_format); + +/* + * drm_sad_to_format - extract channels of an SAD + * @sad: pointer to an sad + * + * extract number of supported channels from byte 0 of SAD + */ +int drm_sad_to_channels(const u8 *sad) +{ + return (sad[0] & DRM_ELD_SAD_CHANNELS_MASK) + 1; +} +EXPORT_SYMBOL(drm_sad_to_channels); + +/* + * drm_sad_to_format - extract supported rates of an SAD + * @sad: pointer to an sad + * + * extract supported rates from byte 1 of SAD + */ +int drm_sad_to_rates(const u8 *sad) +{ + return sad[1] & DRM_ELD_SAD_RATES_MASK; +} +EXPORT_SYMBOL(drm_sad_to_rates); diff --git a/drivers/gpu/drm/i915/display/intel_audio.c b/drivers/gpu/drm/i915/display/intel_audio.c index 6c9ee905f132..ac425b652331 100644 --- a/drivers/gpu/drm/i915/display/intel_audio.c +++ b/drivers/gpu/drm/i915/display/intel_audio.c @@ -1235,7 +1235,33 @@ static int i915_audio_component_get_eld(struct device *kdev, int port, if (*enabled) { eld = intel_encoder->audio_connector->eld; ret = drm_eld_size(eld); - memcpy(buf, eld, min(max_bytes, ret)); + + if (intel_encoder->sad_mask_valid) { + int i; + u8 *temp_buf; + u8 *sad; + + temp_buf = kzalloc(ret, GFP_KERNEL); + + if (!temp_buf) { + mutex_unlock(&dev_priv->audio.mutex); + return -ENOMEM; + } + + memcpy(temp_buf, eld, ret); + + sad = (u8 *)drm_eld_sad(temp_buf); + + for (i = 0; i < drm_eld_sad_count(temp_buf); i++, sad += 3) { + if (!(intel_encoder->supported_sads & (1 << i))) + memset(&sad[0], 0, 3); + } + + memcpy(buf, temp_buf, min(max_bytes, ret)); + kfree(temp_buf); + } else { + memcpy(buf, eld, min(max_bytes, ret)); + } } mutex_unlock(&dev_priv->audio.mutex); @@ -1408,3 +1434,40 @@ void intel_audio_deinit(struct drm_i915_private *dev_priv) else i915_audio_component_cleanup(dev_priv); } + +void intel_eld_compute_config(struct intel_encoder *encoder, + const struct intel_crtc_state *pipe_config, + const struct drm_connector_state *conn_state) +{ + struct drm_connector *connector = conn_state->connector; + u8 *eld = connector->eld; + const u8 *sad = drm_eld_sad(eld); + struct drm_i915_private *dev_priv = to_i915(encoder->base.dev); + u32 *supported_sads = &encoder->supported_sads; + int i, channels; + + mutex_lock(&dev_priv->audio.mutex); + + /* reset information about supported sads to default */ + *supported_sads = 0; + encoder->sad_mask_valid = false; + + /* Currently filtering SADs is necessary only for GLK due to it's + * hardware limitations. However, this function can be scaled + * to any scenario where display driver has to filter out certain + * SADs before exposing them to the audio driver. + */ + if (IS_GEMINILAKE(dev_priv) && + intel_crtc_has_type(pipe_config, INTEL_OUTPUT_DP)) { + encoder->sad_mask_valid = true; + + for (i = 0; i < drm_eld_sad_count(eld); i++, sad += 3) { + channels = drm_sad_to_channels(sad); + + if (channels <= 2) + (*supported_sads) |= 1 << i; + } + } + drm_dbg_kms(&dev_priv->drm, "supported_sads 0x%x\n", *supported_sads); + mutex_unlock(&dev_priv->audio.mutex); +} diff --git a/drivers/gpu/drm/i915/display/intel_audio.h b/drivers/gpu/drm/i915/display/intel_audio.h index 63b22131dc45..17c468a9e07e 100644 --- a/drivers/gpu/drm/i915/display/intel_audio.h +++ b/drivers/gpu/drm/i915/display/intel_audio.h @@ -22,5 +22,8 @@ void intel_audio_cdclk_change_pre(struct drm_i915_private *dev_priv); void intel_audio_cdclk_change_post(struct drm_i915_private *dev_priv); void intel_audio_init(struct drm_i915_private *dev_priv); void intel_audio_deinit(struct drm_i915_private *dev_priv); +void intel_eld_compute_config(struct intel_encoder *encoder, + const struct intel_crtc_state *pipe_config, + const struct drm_connector_state *conn_state); #endif /* __INTEL_AUDIO_H__ */ diff --git a/drivers/gpu/drm/i915/display/intel_ddi.c b/drivers/gpu/drm/i915/display/intel_ddi.c index 6c43a5124cb8..e7807500c88d 100644 --- a/drivers/gpu/drm/i915/display/intel_ddi.c +++ b/drivers/gpu/drm/i915/display/intel_ddi.c @@ -3678,6 +3678,8 @@ static int intel_ddi_compute_config(struct intel_encoder *encoder, intel_ddi_compute_min_voltage_level(dev_priv, pipe_config); + intel_eld_compute_config(encoder, pipe_config, conn_state); + return 0; } diff --git a/drivers/gpu/drm/i915/display/intel_display_types.h b/drivers/gpu/drm/i915/display/intel_display_types.h index 0da9b208d56e..5b6a694ff0cc 100644 --- a/drivers/gpu/drm/i915/display/intel_display_types.h +++ b/drivers/gpu/drm/i915/display/intel_display_types.h @@ -265,6 +265,15 @@ struct intel_encoder { /* for communication with audio component; protected by av_mutex */ const struct drm_connector *audio_connector; + /* bitmask to track supported SADs for current audio connector. + * According to HDA spec Rev 1.0a, ELD SAD limit is 15. Using + * a 32 bit mask for future proofing; protected by av_mutex + */ + u32 supported_sads; + + /* indicates if the supported_sads is a valid bitmask; protected by av_mutex */ + bool sad_mask_valid; + /* VBT information for this encoder (may be NULL for older platforms) */ const struct intel_bios_encoder_data *devdata; }; diff --git a/include/drm/drm_edid.h b/include/drm/drm_edid.h index 2181977ae683..363f4487cdd6 100644 --- a/include/drm/drm_edid.h +++ b/include/drm/drm_edid.h @@ -318,6 +318,11 @@ struct detailed_timing { #define DRM_ELD_CEA_SAD(mnl, sad) (20 + (mnl) + 3 * (sad)) +#define DRM_ELD_SAD_FORMAT_MASK 0x78 +#define DRM_ELD_SAD_FORMAT_SHIFT 3 +#define DRM_ELD_SAD_CHANNELS_MASK 0x7 +#define DRM_ELD_SAD_RATES_MASK 0x7f + struct edid { u8 header[8]; /* Vendor & product info */ @@ -378,6 +383,10 @@ int drm_edid_to_speaker_allocation(const struct edid *edid, u8 **sadb); int drm_av_sync_delay(struct drm_connector *connector, const struct drm_display_mode *mode); +int drm_sad_to_format(const u8 *sad); +int drm_sad_to_channels(const u8 *sad); +int drm_sad_to_rates(const u8 *sad); + #ifdef CONFIG_DRM_LOAD_EDID_FIRMWARE struct edid *drm_load_edid_firmware(struct drm_connector *connector); int __drm_set_edid_firmware_path(const char *path); -- 2.25.1