<html> <head> <base href="https://bugs.freedesktop.org/"> </head> <body> <div> <a class="bz_bug_link bz_status_NEEDINFO " title="NEEDINFO - [KBL] intel NUC6CAYH no LSPCON HDMI audio output" href="https://bugs.freedesktop.org/show_bug.cgi?id=101583#c28">Comment # 28</a> on <a class="bz_bug_link bz_status_NEEDINFO " title="NEEDINFO - [KBL] intel NUC6CAYH no LSPCON HDMI audio output" href="https://bugs.freedesktop.org/show_bug.cgi?id=101583">bug 101583</a> from <a class="email" href="mailto:jnuzman@gmail.com" title="Joseph Nuzman <jnuzman@gmail.com>"> Joseph Nuzman</a> <pre>Posting to this bug, as <a class="bz_bug_link bz_status_CLOSED bz_closed" title="CLOSED DUPLICATE - [SKL] No HDMI audio on Intel NUC6i7KYK, experimental patch workaround" href="show_bug.cgi?id=101793">https://bugs.freedesktop.org/show_bug.cgi?id=101793</a> was marked as duplicate. I found some time to track down why ELD connector type was coming up as HDMI rather than DP. The ELD for a connector is set using the drm_edid_to_eld() routine (in i915, reached by get_modes helper). This drm routine leaves the connector type field of the ELD for the driver to set. [ 2.172863] [drm:drm_edid_to_eld [drm]] ELD monitor SAMSUNG Later, the intel_audio_codec_enable() routine sets the connector type field in ELD correctly as DP. Note, however, that the enable routine is only called once. [ 2.429813] [drm:intel_audio_codec_enable [i915]] ELD on [CONNECTOR:48:DP-1], [ENCODER:47:DDI B] The audio driver will request a copy of the ELD. But before that happens, the drm_edid_to_eld() routine is invoked again, overwriting the ELD and resetting the connector type previously set. [ 2.877015] [drm:drm_edid_to_eld [drm]] ELD monitor SAMSUNG After this, the audio driver invokes a call back to get a copy of the ELD. This is already missing the corrected connector type field. [ 3.020995] [drm:i915_audio_component_get_eld [i915]] Not valid for port B Both the drm_edid_to_eld() and i915_audio_component_get_eld() routines will be called multiple times later, but the connector type field is never set again. The attached patch sets the connector type field after each time the intel_connector_update_modes() helper rewrites the ELD. With the patch applied, connector type is detected correctly by the audio driver as DP, and HDMI audio works on my SKL NUC. $ cat /proc/asound/card0/eld#2.0 monitor_present 1 eld_valid 1 monitor_name SAMSUNG connection_type DisplayPort eld_version [0x2] CEA-861D or below edid_version [0x3] CEA-861-B, C or D manufacture_id 0x2d4c product_id 0xa7a port_id 0x0 support_hdcp 0 support_ai 1 audio_sync_delay 0 speakers [0x1] FL/FR sad_count 1 sad0_coding_type [0x1] LPCM sad0_channels 2 sad0_rates [0xe0] 32000 44100 48000 sad0_bits [0xe0000] 16 20 24 Note that the intel_audio_codec_enable() routine is also setting the audio delay field in the ELD. It may be that this field should also be set by the intel_connector_update_modes() routine. It seems that the audio driver only uses this field to expose the audio_sync_delay in procfs.</pre> </div> <hr> You are receiving this mail because: <ul> <li>You are the QA Contact for the bug.</li> <li>You are on the CC list for the bug.</li> </ul> </body> </html>