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drm/vc4: hdmi: Remove firmware logic for MAI threshold setting

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This was a workaround for bugs in hardware on earlier Pi models
and wasn't totally successful.

It makes audio quality worse on a Pi4 at the higher sample rates

Signed-off-by: Dom Cobley <popcornmix@gmail.com>
Signed-off-by: Maxime Ripard <maxime@cerno.tech>
Link: https://patchwork.freedesktop.org/patch/msgid/20210525132354.297468-10-maxime@cerno.tech
This commit is contained in:
Dom Cobley 2021-05-25 15:23:51 +02:00 committed by Maxime Ripard
parent 9a8fd277a8
commit 8434111ccf
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GPG key ID: E3EF0D6F671851C5
1 changed files with 6 additions and 16 deletions
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22
drivers/gpu/drm/vc4/vc4_hdmi.c
View file

@ -1380,22 +1380,12 @@ static int vc4_hdmi_audio_hw_params(struct snd_pcm_substream *substream,
audio_packet_config |= VC4_SET_FIELD(channel_mask,
VC4_HDMI_AUDIO_PACKET_CEA_MASK);
/* Set the MAI threshold. This logic mimics the firmware's. */
if (vc4_hdmi->audio.samplerate > 96000) {
HDMI_WRITE(HDMI_MAI_THR,
VC4_SET_FIELD(0x12, VC4_HD_MAI_THR_DREQHIGH) |
VC4_SET_FIELD(0x12, VC4_HD_MAI_THR_DREQLOW));
} else if (vc4_hdmi->audio.samplerate > 48000) {
HDMI_WRITE(HDMI_MAI_THR,
VC4_SET_FIELD(0x14, VC4_HD_MAI_THR_DREQHIGH) |
VC4_SET_FIELD(0x12, VC4_HD_MAI_THR_DREQLOW));
} else {
HDMI_WRITE(HDMI_MAI_THR,
VC4_SET_FIELD(0x10, VC4_HD_MAI_THR_PANICHIGH) |
VC4_SET_FIELD(0x10, VC4_HD_MAI_THR_PANICLOW) |
VC4_SET_FIELD(0x10, VC4_HD_MAI_THR_DREQHIGH) |
VC4_SET_FIELD(0x10, VC4_HD_MAI_THR_DREQLOW));
}
/* Set the MAI threshold */
HDMI_WRITE(HDMI_MAI_THR,
VC4_SET_FIELD(0x10, VC4_HD_MAI_THR_PANICHIGH) |
VC4_SET_FIELD(0x10, VC4_HD_MAI_THR_PANICLOW) |
VC4_SET_FIELD(0x10, VC4_HD_MAI_THR_DREQHIGH) |
VC4_SET_FIELD(0x10, VC4_HD_MAI_THR_DREQLOW));
HDMI_WRITE(HDMI_MAI_CONFIG,
VC4_HDMI_MAI_CONFIG_BIT_REVERSE |