ALSA: hda - Reset sample sizes and max bitrates when reading ELD

When a new HDMI/DP device is plugged in, hdmi_update_short_audio_desc()
is called for every SAD (Short Audio Descriptor) in the ELD data. For
LPCM coding type SAD defines the supported sample sizes. For several
other coding types (such as AC-3), a maximum bitrate is defined.

The maximum bitrate and sample size fields are not always cleared.
Therefore, if a device is unplugged and a different one is plugged in,
and the coding types of some SAD positions differ between the devices,
the old max_bitrate or sample_bits values will persist if the new SADs
do not define those values.

The leftover max_bitrate and sample_bits do not cause any issues other
than wrongly showing up in eld#X.Y procfs file and kernel log.

Fix that by always clearing sample_bits and max_bitrate when reading
SADs.

Signed-off-by: Anssi Hannula <anssi.hannula@iki.fi>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

1 files changed, 3 insertions, 1 deletions

diff --git a/sound/pci/hda/hda_eld.c b/sound/pci/hda/hda_eld.c
index 009031fae2b..4a663471dad 100644
--- a/sound/pci/hda/hda_eld.c
+++ b/sound/pci/hda/hda_eld.c
@@ -189,6 +189,9 @@ static void hdmi_update_short_audio_desc(struct cea_sad *a,
         a->channels = GRAB_BITS(buf, 0, 0, 3);
         a->channels++;
 
+        a->sample_bits = 0;
+        a->max_bitrate = 0;
+
         a->format = GRAB_BITS(buf, 0, 3, 4);
         switch (a->format) {
         case AUDIO_CODING_TYPE_REF_STREAM_HEADER:
@@ -198,7 +201,6 @@ static void hdmi_update_short_audio_desc(struct cea_sad *a,
 
         case AUDIO_CODING_TYPE_LPCM:
                 val = GRAB_BITS(buf, 2, 0, 3);
-                a->sample_bits = 0;
                 for (i = 0; i < 3; i++)
                         if (val & (1 << i))
                                 a->sample_bits |= cea_sample_sizes[i + 1];