[PATCH 3/3] drm/radeon: add audio support for DCE6/8 GPUs (v10)

[Rafał Miłecki]

2013/8/14 Alex Deucher <alexdeucher at gmail.com>:
> +       /* program the speaker allocation */
> +       tmp = RREG32_ENDPOINT(offset, AZ_F0_CODEC_PIN_CONTROL_CHANNEL_SPEAKER);
> +       tmp &= ~(DP_CONNECTION | SPEAKER_ALLOCATION_MASK);
> +       /* set HDMI mode */
> +       tmp |= HDMI_CONNECTION;
> +       if (sadb_count)
> +               tmp |= SPEAKER_ALLOCATION(sadb[0]);
> +       else
> +               tmp |= SPEAKER_ALLOCATION(5); /* stereo */
> +       WREG32_ENDPOINT(offset, AZ_F0_CODEC_PIN_CONTROL_CHANNEL_SPEAKER, tmp);
> +
> +       for (i = 0; i < ARRAY_SIZE(eld_reg_to_type); i++) {
> +               u32 value = 0;
> +               int j;
> +
> +               for (j = 0; j < sad_count; j++) {
> +                       struct cea_sad *sad = &sads[j];
> +
> +                       if (sad->format == eld_reg_to_type[i][1]) {
> +                               value = MAX_CHANNELS(sad->channels) |
> +                                       DESCRIPTOR_BYTE_2(sad->byte2) |
> +                                       SUPPORTED_FREQUENCIES(sad->freq);
> +                               if (sad->format == HDMI_AUDIO_CODING_TYPE_PCM)
> +                                       value |= SUPPORTED_FREQUENCIES_STEREO(sad->freq);
> +                               break;
> +                       }
> +               }
> +               WREG32_ENDPOINT(offset, eld_reg_to_type[i][0], value);
> +       }

I hope this is my last questions I'm bothering you with... This is how
fglrx does that part:

WREG32(0x00005e00, 0x00000125);    PIN_CONTROL_CHANNEL_SPEAKER
WREG32(0x00005e04, 0x00c1005f);    PIN_CONTROL_CHANNEL_SPEAKER

RREG32(0x000..05c); -> 0x00000000    AFMT_AUDIO_PACKET_CONTROL2
WREG32(0x000..05c, 0x0000ff00);    AFMT_AUDIO_PACKET_CONTROL2

WREG32(0x00005e00, 0x00000027);    0x27 was 0x00005f80 on Evergreen
RREG32(0x00005e04); -> 0x00000000    0x27 was 0x00005f80 on Evergreen

WREG32(0x00005e00, 0x00000127);    0x27 was 0x00005f80
WREG32(0x00005e04, 0x00000040);    0x27 was 0x00005f80

WREG32(0x00005e00, 0x000c3128);    DESCRIPTOR0
WREG32(0x00005e04, 0x7f077f07);    DESCRIPTOR0

The difference is that between setting PIN_CONTROL_CHANNEL_SPEAKER and
DESCRIPTOR0 fglrx enables audio channels (see
AFMT_AUDIO_PACKET_CONTROL2 and 0xff00).

Do you think it does matter? Or can we ignore the order and do it your way?