ALSA: hda - hdmi: Fix wrong baseline length in ATI/AMD generated ELD

[platform/adaptation/renesas_rcar/renesas_kernel.git] / sound / pci / hda / hda_eld.c

diff --git a/sound/pci/hda/hda_eld.c b/sound/pci/hda/hda_eld.c
index e8c55f5..79ca80f 100644 (file)
--- a/sound/pci/hda/hda_eld.c
+++ b/sound/pci/hda/hda_eld.c
@@ -768,21 +768,39 @@ int snd_hdmi_get_eld_ati(struct hda_codec *codec, hda_nid_t nid,
                return -EINVAL;
        }
 
+       /*
+        * HDMI VSDB latency format:
+        * separately for both audio and video:
+        *  0          field not valid or unknown latency
+        *  [1..251]   msecs = (x-1)*2  (max 500ms with x = 251 = 0xfb)
+        *  255        audio/video not supported
+        *
+        * HDA latency format:
+        * single value indicating video latency relative to audio:
+        *  0          unknown or 0ms
+        *  [1..250]   msecs = x*2  (max 500ms with x = 250 = 0xfa)
+        *  [251..255] reserved
+        */
        aud_synch = snd_hda_codec_read(codec, nid, 0, ATI_VERB_GET_AUDIO_VIDEO_DELAY, 0);
        if ((aud_synch & ATI_DELAY_VIDEO_LATENCY) && (aud_synch & ATI_DELAY_AUDIO_LATENCY)) {
-               int video_latency = (aud_synch & ATI_DELAY_VIDEO_LATENCY) - 1;
-               int audio_latency = ((aud_synch & ATI_DELAY_AUDIO_LATENCY) >> 8) - 1;
+               int video_latency_hdmi = (aud_synch & ATI_DELAY_VIDEO_LATENCY);
+               int audio_latency_hdmi = (aud_synch & ATI_DELAY_AUDIO_LATENCY) >> 8;
 
-               if (video_latency > audio_latency)
-                       buf[6] = min(video_latency - audio_latency, 0xfa);
+               if (video_latency_hdmi <= 0xfb && audio_latency_hdmi <= 0xfb &&
+                   video_latency_hdmi > audio_latency_hdmi)
+                       buf[6] = video_latency_hdmi - audio_latency_hdmi;
+               /* else unknown/invalid or 0ms or video ahead of audio, so use zero */
        }
 
-       /* Baseline length */
-       buf[2] = pos - 4;
-
        /* SAD count */
        buf[5] |= ((pos - ELD_FIXED_BYTES - sink_desc_len) / 3) << 4;
 
+       /* Baseline ELD block length is 4-byte aligned */
+       pos = round_up(pos, 4);
+
+       /* Baseline ELD length (4-byte header is not counted in) */
+       buf[2] = (pos - 4) / 4;
+
        *eld_size = pos;
 
        return 0;