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

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[ Upstream commit 8434111ccfec8fc0549ec325a632067232d38e14 ]

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
Signed-off-by: Sasha Levin <sashal@kernel.org>
This commit is contained in:
Dom Cobley 2021-05-25 15:23:51 +02:00 committed by Greg Kroah-Hartman
parent cefc8e7e0e
commit b161b27067
1 changed files with 6 additions and 16 deletions
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22
drivers/gpu/drm/vc4/vc4_hdmi.c
View File

@ -1031,22 +1031,12 @@ 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 |