Commit 1ee3e217 authored by Jani Nikula's avatar Jani Nikula
Browse files

drm/edid: fix and clarify HDMI VSDB audio latency parsing 



Add helpers for Latency_Fields_Present and I_Latency_Fields_Present
bits, and fix the parsing:

- Respect specification regarding "I_Latency_Fields_Present shall be
  zero if Latency_Fields_Present is zero".

- Don't claim latency fields are present if the data block isn't big
  enough to hold them.

Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: default avatarJani Nikula <jani.nikula@intel.com>
Reviewed-by: default avatarVille Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/80426772a2d2e17bebf6f58d99b7d0cf6260c2d6.1672826282.git.jani.nikula@intel.com
parent c54e2e23

drivers/gpu/drm/drm_edid.c

+19 −8
Original line number Diff line number Diff line
@@ -4685,6 +4685,16 @@ static int add_3d_struct_modes(struct drm_connector *connector, u16 structure, 
	return modes;

}



static bool hdmi_vsdb_latency_present(const u8 *db)

{

	return db[8] & BIT(7);

}



static bool hdmi_vsdb_i_latency_present(const u8 *db)

{

	return hdmi_vsdb_latency_present(db) && db[8] & BIT(6);

}



/*

 * do_hdmi_vsdb_modes - Parse the HDMI Vendor Specific data block

 * @connector: connector corresponding to the HDMI sink
@@ -5357,6 +5367,7 @@ drm_parse_hdr_metadata_block(struct drm_connector *connector, const u8 *db) 
	}

}



/* HDMI Vendor-Specific Data Block (HDMI VSDB, H14b-VSDB) */

static void

drm_parse_hdmi_vsdb_audio(struct drm_connector *connector, const u8 *db)

{
@@ -5364,18 +5375,18 @@ drm_parse_hdmi_vsdb_audio(struct drm_connector *connector, const u8 *db) 


	if (len >= 6 && (db[6] & (1 << 7)))

		connector->eld[DRM_ELD_SAD_COUNT_CONN_TYPE] |= DRM_ELD_SUPPORTS_AI;

	if (len >= 8) {

		connector->latency_present[0] = db[8] >> 7;

		connector->latency_present[1] = (db[8] >> 6) & 1;

	}

	if (len >= 9)



	if (len >= 10 && hdmi_vsdb_latency_present(db)) {

		connector->latency_present[0] = true;

		connector->video_latency[0] = db[9];

	if (len >= 10)

		connector->audio_latency[0] = db[10];

	if (len >= 11)

	}



	if (len >= 12 && hdmi_vsdb_i_latency_present(db)) {

		connector->latency_present[1] = true;

		connector->video_latency[1] = db[11];

	if (len >= 12)

		connector->audio_latency[1] = db[12];

	}



	drm_dbg_kms(connector->dev,

		    "[CONNECTOR:%d:%s] HDMI: latency present %d %d, video latency %d %d, audio latency %d %d\n",